diff options
| author | Graham Wilson <graham@mknod.org> | 2004-11-29 16:40:04 +0000 |
|---|---|---|
| committer | Graham Wilson <graham@mknod.org> | 2004-11-29 16:40:04 +0000 |
| commit | fdec8d6cf10bfd061d98d8b790bb71985ed36e3a (patch) | |
| tree | 5dcdc4652472a06e8be717237d66b17e74708666 /RFC/rfc2060.txt | |
| parent | 100fa76e5f1675dd18b9d35e5c7e88699a57ba7d (diff) | |
| download | fetchmail-fdec8d6cf10bfd061d98d8b790bb71985ed36e3a.tar.gz fetchmail-fdec8d6cf10bfd061d98d8b790bb71985ed36e3a.tar.bz2 fetchmail-fdec8d6cf10bfd061d98d8b790bb71985ed36e3a.zip | |
Remove RFCs from the trunk, since we don't distribute them anyways. All of the removed RFCs are listed in the design-notes.html file, with the exception of NNTP (RFC977). Also add a link to the "LAN Mail Protocols" document to the design-notes.html file.
svn path=/trunk/; revision=4013
Diffstat (limited to 'RFC/rfc2060.txt')
| -rw-r--r-- | RFC/rfc2060.txt | 4595 |
1 files changed, 0 insertions, 4595 deletions
diff --git a/RFC/rfc2060.txt b/RFC/rfc2060.txt deleted file mode 100644 index 591dec4d..00000000 --- a/RFC/rfc2060.txt +++ /dev/null @@ -1,4595 +0,0 @@ - - - - - - -Network Working Group M. Crispin -Request for Comments: 2060 University of Washington -Obsoletes: 1730 December 1996 -Category: Standards Track - - - INTERNET MESSAGE ACCESS PROTOCOL - VERSION 4rev1 - -Status of this Memo - - This document specifies an Internet standards track protocol for the - Internet community, and requests discussion and suggestions for - improvements. Please refer to the current edition of the "Internet - Official Protocol Standards" (STD 1) for the standardization state - and status of this protocol. Distribution of this memo is unlimited. - -Abstract - - The Internet Message Access Protocol, Version 4rev1 (IMAP4rev1) - allows a client to access and manipulate electronic mail messages on - a server. IMAP4rev1 permits manipulation of remote message folders, - called "mailboxes", in a way that is functionally equivalent to local - mailboxes. IMAP4rev1 also provides the capability for an offline - client to resynchronize with the server (see also [IMAP-DISC]). - - IMAP4rev1 includes operations for creating, deleting, and renaming - mailboxes; checking for new messages; permanently removing messages; - setting and clearing flags; [RFC-822] and [MIME-IMB] parsing; - searching; and selective fetching of message attributes, texts, and - portions thereof. Messages in IMAP4rev1 are accessed by the use of - numbers. These numbers are either message sequence numbers or unique - identifiers. - - IMAP4rev1 supports a single server. A mechanism for accessing - configuration information to support multiple IMAP4rev1 servers is - discussed in [ACAP]. - - IMAP4rev1 does not specify a means of posting mail; this function is - handled by a mail transfer protocol such as [SMTP]. - - IMAP4rev1 is designed to be upwards compatible from the [IMAP2] and - unpublished IMAP2bis protocols. In the course of the evolution of - IMAP4rev1, some aspects in the earlier protocol have become obsolete. - Obsolete commands, responses, and data formats which an IMAP4rev1 - implementation may encounter when used with an earlier implementation - are described in [IMAP-OBSOLETE]. - - - - - -Crispin Standards Track [Page 1] - -RFC 2060 IMAP4rev1 December 1996 - - - Other compatibility issues with IMAP2bis, the most common variant of - the earlier protocol, are discussed in [IMAP-COMPAT]. A full - discussion of compatibility issues with rare (and presumed extinct) - variants of [IMAP2] is in [IMAP-HISTORICAL]; this document is - primarily of historical interest. - -Table of Contents - -IMAP4rev1 Protocol Specification .................................. 4 -1. How to Read This Document ................................. 4 -1.1. Organization of This Document ............................. 4 -1.2. Conventions Used in This Document ......................... 4 -2. Protocol Overview ......................................... 5 -2.1. Link Level ................................................ 5 -2.2. Commands and Responses .................................... 6 -2.2.1. Client Protocol Sender and Server Protocol Receiver ....... 6 -2.2.2. Server Protocol Sender and Client Protocol Receiver ....... 7 -2.3. Message Attributes ........................................ 7 -2.3.1. Message Numbers ........................................... 7 -2.3.1.1. Unique Identifier (UID) Message Attribute ......... 7 -2.3.1.2. Message Sequence Number Message Attribute ......... 9 -2.3.2. Flags Message Attribute .................................... 9 -2.3.3. Internal Date Message Attribute ........................... 10 -2.3.4. [RFC-822] Size Message Attribute .......................... 11 -2.3.5. Envelope Structure Message Attribute ...................... 11 -2.3.6. Body Structure Message Attribute .......................... 11 -2.4. Message Texts ............................................. 11 -3. State and Flow Diagram .................................... 11 -3.1. Non-Authenticated State ................................... 11 -3.2. Authenticated State ....................................... 11 -3.3. Selected State ............................................ 12 -3.4. Logout State .............................................. 12 -4. Data Formats .............................................. 12 -4.1. Atom ...................................................... 13 -4.2. Number .................................................... 13 -4.3. String ..................................................... 13 -4.3.1. 8-bit and Binary Strings .................................. 13 -4.4. Parenthesized List ........................................ 14 -4.5. NIL ....................................................... 14 -5. Operational Considerations ................................ 14 -5.1. Mailbox Naming ............................................ 14 -5.1.1. Mailbox Hierarchy Naming .................................. 14 -5.1.2. Mailbox Namespace Naming Convention ....................... 14 -5.1.3. Mailbox International Naming Convention ................... 15 -5.2. Mailbox Size and Message Status Updates ................... 16 -5.3. Response when no Command in Progress ...................... 16 -5.4. Autologout Timer .......................................... 16 -5.5. Multiple Commands in Progress ............................. 17 - - - -Crispin Standards Track [Page 2] - -RFC 2060 IMAP4rev1 December 1996 - - -6. Client Commands ........................................... 17 -6.1. Client Commands - Any State ............................... 18 -6.1.1. CAPABILITY Command ........................................ 18 -6.1.2. NOOP Command .............................................. 19 -6.1.3. LOGOUT Command ............................................ 20 -6.2. Client Commands - Non-Authenticated State ................. 20 -6.2.1. AUTHENTICATE Command ...................................... 21 -6.2.2. LOGIN Command ............................................. 22 -6.3. Client Commands - Authenticated State ..................... 22 -6.3.1. SELECT Command ............................................ 23 -6.3.2. EXAMINE Command ........................................... 24 -6.3.3. CREATE Command ............................................ 25 -6.3.4. DELETE Command ............................................ 26 -6.3.5. RENAME Command ............................................ 27 -6.3.6. SUBSCRIBE Command ......................................... 29 -6.3.7. UNSUBSCRIBE Command ....................................... 30 -6.3.8. LIST Command .............................................. 30 -6.3.9. LSUB Command .............................................. 32 -6.3.10. STATUS Command ............................................ 33 -6.3.11. APPEND Command ............................................ 34 -6.4. Client Commands - Selected State .......................... 35 -6.4.1. CHECK Command ............................................. 36 -6.4.2. CLOSE Command ............................................. 36 -6.4.3. EXPUNGE Command ........................................... 37 -6.4.4. SEARCH Command ............................................ 37 -6.4.5. FETCH Command ............................................. 41 -6.4.6. STORE Command ............................................. 45 -6.4.7. COPY Command .............................................. 46 -6.4.8. UID Command ............................................... 47 -6.5. Client Commands - Experimental/Expansion .................. 48 -6.5.1. X<atom> Command ........................................... 48 -7. Server Responses .......................................... 48 -7.1. Server Responses - Status Responses ....................... 49 -7.1.1. OK Response ............................................... 51 -7.1.2. NO Response ............................................... 51 -7.1.3. BAD Response .............................................. 52 -7.1.4. PREAUTH Response .......................................... 52 -7.1.5. BYE Response .............................................. 52 -7.2. Server Responses - Server and Mailbox Status .............. 53 -7.2.1. CAPABILITY Response ....................................... 53 -7.2.2. LIST Response .............................................. 54 -7.2.3. LSUB Response ............................................. 55 -7.2.4 STATUS Response ........................................... 55 -7.2.5. SEARCH Response ........................................... 55 -7.2.6. FLAGS Response ............................................ 56 -7.3. Server Responses - Mailbox Size ........................... 56 -7.3.1. EXISTS Response ........................................... 56 -7.3.2. RECENT Response ........................................... 57 - - - -Crispin Standards Track [Page 3] - -RFC 2060 IMAP4rev1 December 1996 - - -7.4. Server Responses - Message Status ......................... 57 -7.4.1. EXPUNGE Response .......................................... 57 -7.4.2. FETCH Response ............................................ 58 -7.5. Server Responses - Command Continuation Request ........... 63 -8. Sample IMAP4rev1 connection ............................... 63 -9. Formal Syntax ............................................. 64 -10. Author's Note ............................................. 74 -11. Security Considerations ................................... 74 -12. Author's Address .......................................... 75 -Appendices ........................................................ 76 -A. References ................................................ 76 -B. Changes from RFC 1730 ..................................... 77 -C. Key Word Index ............................................ 79 - - -IMAP4rev1 Protocol Specification - -1. How to Read This Document - -1.1. Organization of This Document - - This document is written from the point of view of the implementor of - an IMAP4rev1 client or server. Beyond the protocol overview in - section 2, it is not optimized for someone trying to understand the - operation of the protocol. The material in sections 3 through 5 - provides the general context and definitions with which IMAP4rev1 - operates. - - Sections 6, 7, and 9 describe the IMAP commands, responses, and - syntax, respectively. The relationships among these are such that it - is almost impossible to understand any of them separately. In - particular, do not attempt to deduce command syntax from the command - section alone; instead refer to the Formal Syntax section. - -1.2. Conventions Used in This Document - - In examples, "C:" and "S:" indicate lines sent by the client and - server respectively. - - The following terms are used in this document to signify the - requirements of this specification. - - 1) MUST, or the adjective REQUIRED, means that the definition is - an absolute requirement of the specification. - - 2) MUST NOT that the definition is an absolute prohibition of the - specification. - - - - -Crispin Standards Track [Page 4] - -RFC 2060 IMAP4rev1 December 1996 - - - 3) SHOULD means that there may exist valid reasons in particular - circumstances to ignore a particular item, but the full - implications MUST be understood and carefully weighed before - choosing a different course. - - 4) SHOULD NOT means that there may exist valid reasons in - particular circumstances when the particular behavior is - acceptable or even useful, but the full implications SHOULD be - understood and the case carefully weighed before implementing - any behavior described with this label. - - 5) MAY, or the adjective OPTIONAL, means that an item is truly - optional. One vendor may choose to include the item because a - particular marketplace requires it or because the vendor feels - that it enhances the product while another vendor may omit the - same item. An implementation which does not include a - particular option MUST be prepared to interoperate with another - implementation which does include the option. - - "Can" is used instead of "may" when referring to a possible - circumstance or situation, as opposed to an optional facility of - the protocol. - - "User" is used to refer to a human user, whereas "client" refers - to the software being run by the user. - - "Connection" refers to the entire sequence of client/server - interaction from the initial establishment of the network - connection until its termination. "Session" refers to the - sequence of client/server interaction from the time that a mailbox - is selected (SELECT or EXAMINE command) until the time that - selection ends (SELECT or EXAMINE of another mailbox, CLOSE - command, or connection termination). - - Characters are 7-bit US-ASCII unless otherwise specified. Other - character sets are indicated using a "CHARSET", as described in - [MIME-IMT] and defined in [CHARSET]. CHARSETs have important - additional semantics in addition to defining character set; refer - to these documents for more detail. - -2. Protocol Overview - -2.1. Link Level - - The IMAP4rev1 protocol assumes a reliable data stream such as - provided by TCP. When TCP is used, an IMAP4rev1 server listens on - port 143. - - - - -Crispin Standards Track [Page 5] - -RFC 2060 IMAP4rev1 December 1996 - - -2.2. Commands and Responses - - An IMAP4rev1 connection consists of the establishment of a - client/server network connection, an initial greeting from the - server, and client/server interactions. These client/server - interactions consist of a client command, server data, and a server - completion result response. - - All interactions transmitted by client and server are in the form of - lines; that is, strings that end with a CRLF. The protocol receiver - of an IMAP4rev1 client or server is either reading a line, or is - reading a sequence of octets with a known count followed by a line. - -2.2.1. Client Protocol Sender and Server Protocol Receiver - - The client command begins an operation. Each client command is - prefixed with an identifier (typically a short alphanumeric string, - e.g. A0001, A0002, etc.) called a "tag". A different tag is - generated by the client for each command. - - There are two cases in which a line from the client does not - represent a complete command. In one case, a command argument is - quoted with an octet count (see the description of literal in String - under Data Formats); in the other case, the command arguments require - server feedback (see the AUTHENTICATE command). In either case, the - server sends a command continuation request response if it is ready - for the octets (if appropriate) and the remainder of the command. - This response is prefixed with the token "+". - - Note: If, instead, the server detected an error in the command, it - sends a BAD completion response with tag matching the command (as - described below) to reject the command and prevent the client from - sending any more of the command. - - It is also possible for the server to send a completion response - for some other command (if multiple commands are in progress), or - untagged data. In either case, the command continuation request - is still pending; the client takes the appropriate action for the - response, and reads another response from the server. In all - cases, the client MUST send a complete command (including - receiving all command continuation request responses and command - continuations for the command) before initiating a new command. - - The protocol receiver of an IMAP4rev1 server reads a command line - from the client, parses the command and its arguments, and transmits - server data and a server command completion result response. - - - - - -Crispin Standards Track [Page 6] - -RFC 2060 IMAP4rev1 December 1996 - - -2.2.2. Server Protocol Sender and Client Protocol Receiver - - Data transmitted by the server to the client and status responses - that do not indicate command completion are prefixed with the token - "*", and are called untagged responses. - - Server data MAY be sent as a result of a client command, or MAY be - sent unilaterally by the server. There is no syntactic difference - between server data that resulted from a specific command and server - data that were sent unilaterally. - - The server completion result response indicates the success or - failure of the operation. It is tagged with the same tag as the - client command which began the operation. Thus, if more than one - command is in progress, the tag in a server completion response - identifies the command to which the response applies. There are - three possible server completion responses: OK (indicating success), - NO (indicating failure), or BAD (indicating protocol error such as - unrecognized command or command syntax error). - - The protocol receiver of an IMAP4rev1 client reads a response line - from the server. It then takes action on the response based upon the - first token of the response, which can be a tag, a "*", or a "+". - - A client MUST be prepared to accept any server response at all times. - This includes server data that was not requested. Server data SHOULD - be recorded, so that the client can reference its recorded copy - rather than sending a command to the server to request the data. In - the case of certain server data, the data MUST be recorded. - - This topic is discussed in greater detail in the Server Responses - section. - -2.3. Message Attributes - - In addition to message text, each message has several attributes - associated with it. These attributes may be retrieved individually - or in conjunction with other attributes or message texts. - -2.3.1. Message Numbers - - Messages in IMAP4rev1 are accessed by one of two numbers; the unique - identifier and the message sequence number. - -2.3.1.1. Unique Identifier (UID) Message Attribute - - A 32-bit value assigned to each message, which when used with the - unique identifier validity value (see below) forms a 64-bit value - - - -Crispin Standards Track [Page 7] - -RFC 2060 IMAP4rev1 December 1996 - - - that is permanently guaranteed not to refer to any other message in - the mailbox. Unique identifiers are assigned in a strictly ascending - fashion in the mailbox; as each message is added to the mailbox it is - assigned a higher UID than the message(s) which were added - previously. - - Unlike message sequence numbers, unique identifiers are not - necessarily contiguous. Unique identifiers also persist across - sessions. This permits a client to resynchronize its state from a - previous session with the server (e.g. disconnected or offline access - clients); this is discussed further in [IMAP-DISC]. - - Associated with every mailbox is a unique identifier validity value, - which is sent in an UIDVALIDITY response code in an OK untagged - response at mailbox selection time. If unique identifiers from an - earlier session fail to persist to this session, the unique - identifier validity value MUST be greater than the one used in the - earlier session. - - Note: Unique identifiers MUST be strictly ascending in the mailbox - at all times. If the physical message store is re-ordered by a - non-IMAP agent, this requires that the unique identifiers in the - mailbox be regenerated, since the former unique identifers are no - longer strictly ascending as a result of the re-ordering. Another - instance in which unique identifiers are regenerated is if the - message store has no mechanism to store unique identifiers. - Although this specification recognizes that this may be - unavoidable in certain server environments, it STRONGLY ENCOURAGES - message store implementation techniques that avoid this problem. - - Another cause of non-persistance is if the mailbox is deleted and - a new mailbox with the same name is created at a later date, Since - the name is the same, a client may not know that this is a new - mailbox unless the unique identifier validity is different. A - good value to use for the unique identifier validity value is a - 32-bit representation of the creation date/time of the mailbox. - It is alright to use a constant such as 1, but only if it - guaranteed that unique identifiers will never be reused, even in - the case of a mailbox being deleted (or renamed) and a new mailbox - by the same name created at some future time. - - The unique identifier of a message MUST NOT change during the - session, and SHOULD NOT change between sessions. However, if it is - not possible to preserve the unique identifier of a message in a - subsequent session, each subsequent session MUST have a new unique - identifier validity value that is larger than any that was used - previously. - - - - -Crispin Standards Track [Page 8] - -RFC 2060 IMAP4rev1 December 1996 - - -2.3.1.2. Message Sequence Number Message Attribute - - A relative position from 1 to the number of messages in the mailbox. - This position MUST be ordered by ascending unique identifier. As - each new message is added, it is assigned a message sequence number - that is 1 higher than the number of messages in the mailbox before - that new message was added. - - Message sequence numbers can be reassigned during the session. For - example, when a message is permanently removed (expunged) from the - mailbox, the message sequence number for all subsequent messages is - decremented. Similarly, a new message can be assigned a message - sequence number that was once held by some other message prior to an - expunge. - - In addition to accessing messages by relative position in the - mailbox, message sequence numbers can be used in mathematical - calculations. For example, if an untagged "EXISTS 11" is received, - and previously an untagged "8 EXISTS" was received, three new - messages have arrived with message sequence numbers of 9, 10, and 11. - Another example; if message 287 in a 523 message mailbox has UID - 12345, there are exactly 286 messages which have lesser UIDs and 236 - messages which have greater UIDs. - -2.3.2. Flags Message Attribute - - A list of zero or more named tokens associated with the message. A - flag is set by its addition to this list, and is cleared by its - removal. There are two types of flags in IMAP4rev1. A flag of - either type may be permanent or session-only. - - A system flag is a flag name that is pre-defined in this - specification. All system flags begin with "\". Certain system - flags (\Deleted and \Seen) have special semantics described - elsewhere. The currently-defined system flags are: - - \Seen Message has been read - - \Answered Message has been answered - - \Flagged Message is "flagged" for urgent/special attention - - \Deleted Message is "deleted" for removal by later EXPUNGE - - \Draft Message has not completed composition (marked as a - draft). - - - - - -Crispin Standards Track [Page 9] - -RFC 2060 IMAP4rev1 December 1996 - - - \Recent Message is "recently" arrived in this mailbox. This - session is the first session to have been notified - about this message; subsequent sessions will not see - \Recent set for this message. This flag can not be - altered by the client. - - If it is not possible to determine whether or not - this session is the first session to be notified - about a message, then that message SHOULD be - considered recent. - - If multiple connections have the same mailbox - selected simultaneously, it is undefined which of - these connections will see newly-arrives messages - with \Recent set and which will see it without - \Recent set. - - A keyword is defined by the server implementation. Keywords do - not begin with "\". Servers MAY permit the client to define new - keywords in the mailbox (see the description of the - PERMANENTFLAGS response code for more information). - - A flag may be permanent or session-only on a per-flag basis. - Permanent flags are those which the client can add or remove - from the message flags permanently; that is, subsequent sessions - will see any change in permanent flags. Changes to session - flags are valid only in that session. - - Note: The \Recent system flag is a special case of a - session flag. \Recent can not be used as an argument in a - STORE command, and thus can not be changed at all. - -2.3.3. Internal Date Message Attribute - - The internal date and time of the message on the server. This is not - the date and time in the [RFC-822] header, but rather a date and time - which reflects when the message was received. In the case of - messages delivered via [SMTP], this SHOULD be the date and time of - final delivery of the message as defined by [SMTP]. In the case of - messages delivered by the IMAP4rev1 COPY command, this SHOULD be the - internal date and time of the source message. In the case of - messages delivered by the IMAP4rev1 APPEND command, this SHOULD be - the date and time as specified in the APPEND command description. - All other cases are implementation defined. - - - - - - - -Crispin Standards Track [Page 10] - -RFC 2060 IMAP4rev1 December 1996 - - -2.3.4. [RFC-822] Size Message Attribute - - The number of octets in the message, as expressed in [RFC-822] - format. - -2.3.5. Envelope Structure Message Attribute - - A parsed representation of the [RFC-822] envelope information (not to - be confused with an [SMTP] envelope) of the message. - -2.3.6. Body Structure Message Attribute - - A parsed representation of the [MIME-IMB] body structure information - of the message. - -2.4. Message Texts - - In addition to being able to fetch the full [RFC-822] text of a - message, IMAP4rev1 permits the fetching of portions of the full - message text. Specifically, it is possible to fetch the [RFC-822] - message header, [RFC-822] message body, a [MIME-IMB] body part, or a - [MIME-IMB] header. - -3. State and Flow Diagram - - An IMAP4rev1 server is in one of four states. Most commands are - valid in only certain states. It is a protocol error for the client - to attempt a command while the command is in an inappropriate state. - In this case, a server will respond with a BAD or NO (depending upon - server implementation) command completion result. - -3.1. Non-Authenticated State - - In non-authenticated state, the client MUST supply authentication - credentials before most commands will be permitted. This state is - entered when a connection starts unless the connection has been pre- - authenticated. - -3.2. Authenticated State - - In authenticated state, the client is authenticated and MUST select a - mailbox to access before commands that affect messages will be - permitted. This state is entered when a pre-authenticated connection - starts, when acceptable authentication credentials have been - provided, or after an error in selecting a mailbox. - - - - - - -Crispin Standards Track [Page 11] - -RFC 2060 IMAP4rev1 December 1996 - - -3.3. Selected State - - In selected state, a mailbox has been selected to access. This state - is entered when a mailbox has been successfully selected. - -3.4. Logout State - - In logout state, the connection is being terminated, and the server - will close the connection. This state can be entered as a result of - a client request or by unilateral server decision. - - +--------------------------------------+ - |initial connection and server greeting| - +--------------------------------------+ - || (1) || (2) || (3) - VV || || - +-----------------+ || || - |non-authenticated| || || - +-----------------+ || || - || (7) || (4) || || - || VV VV || - || +----------------+ || - || | authenticated |<=++ || - || +----------------+ || || - || || (7) || (5) || (6) || - || || VV || || - || || +--------+ || || - || || |selected|==++ || - || || +--------+ || - || || || (7) || - VV VV VV VV - +--------------------------------------+ - | logout and close connection | - +--------------------------------------+ - - (1) connection without pre-authentication (OK greeting) - (2) pre-authenticated connection (PREAUTH greeting) - (3) rejected connection (BYE greeting) - (4) successful LOGIN or AUTHENTICATE command - (5) successful SELECT or EXAMINE command - (6) CLOSE command, or failed SELECT or EXAMINE command - (7) LOGOUT command, server shutdown, or connection closed - -4. Data Formats - - IMAP4rev1 uses textual commands and responses. Data in IMAP4rev1 can - be in one of several forms: atom, number, string, parenthesized list, - or NIL. - - - -Crispin Standards Track [Page 12] - -RFC 2060 IMAP4rev1 December 1996 - - -4.1. Atom - - An atom consists of one or more non-special characters. - -4.2. Number - - A number consists of one or more digit characters, and represents a - numeric value. - -4.3. String - - A string is in one of two forms: literal and quoted string. The - literal form is the general form of string. The quoted string form - is an alternative that avoids the overhead of processing a literal at - the cost of limitations of characters that can be used in a quoted - string. - - A literal is a sequence of zero or more octets (including CR and LF), - prefix-quoted with an octet count in the form of an open brace ("{"), - the number of octets, close brace ("}"), and CRLF. In the case of - literals transmitted from server to client, the CRLF is immediately - followed by the octet data. In the case of literals transmitted from - client to server, the client MUST wait to receive a command - continuation request (described later in this document) before - sending the octet data (and the remainder of the command). - - A quoted string is a sequence of zero or more 7-bit characters, - excluding CR and LF, with double quote (<">) characters at each end. - - The empty string is represented as either "" (a quoted string with - zero characters between double quotes) or as {0} followed by CRLF (a - literal with an octet count of 0). - - Note: Even if the octet count is 0, a client transmitting a - literal MUST wait to receive a command continuation request. - -4.3.1. 8-bit and Binary Strings - - 8-bit textual and binary mail is supported through the use of a - [MIME-IMB] content transfer encoding. IMAP4rev1 implementations MAY - transmit 8-bit or multi-octet characters in literals, but SHOULD do - so only when the [CHARSET] is identified. - - - - - - - - - -Crispin Standards Track [Page 13] - -RFC 2060 IMAP4rev1 December 1996 - - - Although a BINARY body encoding is defined, unencoded binary strings - are not permitted. A "binary string" is any string with NUL - characters. Implementations MUST encode binary data into a textual - form such as BASE64 before transmitting the data. A string with an - excessive amount of CTL characters MAY also be considered to be - binary. - -4.4. Parenthesized List - - Data structures are represented as a "parenthesized list"; a sequence - of data items, delimited by space, and bounded at each end by - parentheses. A parenthesized list can contain other parenthesized - lists, using multiple levels of parentheses to indicate nesting. - - The empty list is represented as () -- a parenthesized list with no - members. - -4.5. NIL - - The special atom "NIL" represents the non-existence of a particular - data item that is represented as a string or parenthesized list, as - distinct from the empty string "" or the empty parenthesized list (). - -5. Operational Considerations - -5.1. Mailbox Naming - - The interpretation of mailbox names is implementation-dependent. - However, the case-insensitive mailbox name INBOX is a special name - reserved to mean "the primary mailbox for this user on this server". - -5.1.1. Mailbox Hierarchy Naming - - If it is desired to export hierarchical mailbox names, mailbox names - MUST be left-to-right hierarchical using a single character to - separate levels of hierarchy. The same hierarchy separator character - is used for all levels of hierarchy within a single name. - -5.1.2. Mailbox Namespace Naming Convention - - By convention, the first hierarchical element of any mailbox name - which begins with "#" identifies the "namespace" of the remainder of - the name. This makes it possible to disambiguate between different - types of mailbox stores, each of which have their own namespaces. - - - - - - - -Crispin Standards Track [Page 14] - -RFC 2060 IMAP4rev1 December 1996 - - - For example, implementations which offer access to USENET - newsgroups MAY use the "#news" namespace to partition the USENET - newsgroup namespace from that of other mailboxes. Thus, the - comp.mail.misc newsgroup would have an mailbox name of - "#news.comp.mail.misc", and the name "comp.mail.misc" could refer - to a different object (e.g. a user's private mailbox). - -5.1.3. Mailbox International Naming Convention - - By convention, international mailbox names are specified using a - modified version of the UTF-7 encoding described in [UTF-7]. The - purpose of these modifications is to correct the following problems - with UTF-7: - - 1) UTF-7 uses the "+" character for shifting; this conflicts with - the common use of "+" in mailbox names, in particular USENET - newsgroup names. - - 2) UTF-7's encoding is BASE64 which uses the "/" character; this - conflicts with the use of "/" as a popular hierarchy delimiter. - - 3) UTF-7 prohibits the unencoded usage of "\"; this conflicts with - the use of "\" as a popular hierarchy delimiter. - - 4) UTF-7 prohibits the unencoded usage of "~"; this conflicts with - the use of "~" in some servers as a home directory indicator. - - 5) UTF-7 permits multiple alternate forms to represent the same - string; in particular, printable US-ASCII chararacters can be - represented in encoded form. - - In modified UTF-7, printable US-ASCII characters except for "&" - represent themselves; that is, characters with octet values 0x20-0x25 - and 0x27-0x7e. The character "&" (0x26) is represented by the two- - octet sequence "&-". - - All other characters (octet values 0x00-0x1f, 0x7f-0xff, and all - Unicode 16-bit octets) are represented in modified BASE64, with a - further modification from [UTF-7] that "," is used instead of "/". - Modified BASE64 MUST NOT be used to represent any printing US-ASCII - character which can represent itself. - - "&" is used to shift to modified BASE64 and "-" to shift back to US- - ASCII. All names start in US-ASCII, and MUST end in US-ASCII (that - is, a name that ends with a Unicode 16-bit octet MUST end with a "- - "). - - - - - -Crispin Standards Track [Page 15] - -RFC 2060 IMAP4rev1 December 1996 - - - For example, here is a mailbox name which mixes English, Japanese, - and Chinese text: ~peter/mail/&ZeVnLIqe-/&U,BTFw- - -5.2. Mailbox Size and Message Status Updates - - At any time, a server can send data that the client did not request. - Sometimes, such behavior is REQUIRED. For example, agents other than - the server MAY add messages to the mailbox (e.g. new mail delivery), - change the flags of message in the mailbox (e.g. simultaneous access - to the same mailbox by multiple agents), or even remove messages from - the mailbox. A server MUST send mailbox size updates automatically - if a mailbox size change is observed during the processing of a - command. A server SHOULD send message flag updates automatically, - without requiring the client to request such updates explicitly. - Special rules exist for server notification of a client about the - removal of messages to prevent synchronization errors; see the - description of the EXPUNGE response for more detail. - - Regardless of what implementation decisions a client makes on - remembering data from the server, a client implementation MUST record - mailbox size updates. It MUST NOT assume that any command after - initial mailbox selection will return the size of the mailbox. - -5.3. Response when no Command in Progress - - Server implementations are permitted to send an untagged response - (except for EXPUNGE) while there is no command in progress. Server - implementations that send such responses MUST deal with flow control - considerations. Specifically, they MUST either (1) verify that the - size of the data does not exceed the underlying transport's available - window size, or (2) use non-blocking writes. - -5.4. Autologout Timer - - If a server has an inactivity autologout timer, that timer MUST be of - at least 30 minutes' duration. The receipt of ANY command from the - client during that interval SHOULD suffice to reset the autologout - timer. - - - - - - - - - - - - - -Crispin Standards Track [Page 16] - -RFC 2060 IMAP4rev1 December 1996 - - -5.5. Multiple Commands in Progress - - The client MAY send another command without waiting for the - completion result response of a command, subject to ambiguity rules - (see below) and flow control constraints on the underlying data - stream. Similarly, a server MAY begin processing another command - before processing the current command to completion, subject to - ambiguity rules. However, any command continuation request responses - and command continuations MUST be negotiated before any subsequent - command is initiated. - - The exception is if an ambiguity would result because of a command - that would affect the results of other commands. Clients MUST NOT - send multiple commands without waiting if an ambiguity would result. - If the server detects a possible ambiguity, it MUST execute commands - to completion in the order given by the client. - - The most obvious example of ambiguity is when a command would affect - the results of another command; for example, a FETCH of a message's - flags and a STORE of that same message's flags. - - A non-obvious ambiguity occurs with commands that permit an untagged - EXPUNGE response (commands other than FETCH, STORE, and SEARCH), - since an untagged EXPUNGE response can invalidate sequence numbers in - a subsequent command. This is not a problem for FETCH, STORE, or - SEARCH commands because servers are prohibited from sending EXPUNGE - responses while any of those commands are in progress. Therefore, if - the client sends any command other than FETCH, STORE, or SEARCH, it - MUST wait for a response before sending a command with message - sequence numbers. - - For example, the following non-waiting command sequences are invalid: - - FETCH + NOOP + STORE - STORE + COPY + FETCH - COPY + COPY - CHECK + FETCH - - The following are examples of valid non-waiting command sequences: - - FETCH + STORE + SEARCH + CHECK - STORE + COPY + EXPUNGE - -6. Client Commands - - IMAP4rev1 commands are described in this section. Commands are - organized by the state in which the command is permitted. Commands - which are permitted in multiple states are listed in the minimum - - - -Crispin Standards Track [Page 17] - -RFC 2060 IMAP4rev1 December 1996 - - - permitted state (for example, commands valid in authenticated and - selected state are listed in the authenticated state commands). - - Command arguments, identified by "Arguments:" in the command - descriptions below, are described by function, not by syntax. The - precise syntax of command arguments is described in the Formal Syntax - section. - - Some commands cause specific server responses to be returned; these - are identified by "Responses:" in the command descriptions below. - See the response descriptions in the Responses section for - information on these responses, and the Formal Syntax section for the - precise syntax of these responses. It is possible for server data to - be transmitted as a result of any command; thus, commands that do not - specifically require server data specify "no specific responses for - this command" instead of "none". - - The "Result:" in the command description refers to the possible - tagged status responses to a command, and any special interpretation - of these status responses. - -6.1. Client Commands - Any State - - The following commands are valid in any state: CAPABILITY, NOOP, and - LOGOUT. - -6.1.1. CAPABILITY Command - - Arguments: none - - Responses: REQUIRED untagged response: CAPABILITY - - Result: OK - capability completed - BAD - command unknown or arguments invalid - - The CAPABILITY command requests a listing of capabilities that the - server supports. The server MUST send a single untagged - CAPABILITY response with "IMAP4rev1" as one of the listed - capabilities before the (tagged) OK response. This listing of - capabilities is not dependent upon connection state or user. It - is therefore not necessary to issue a CAPABILITY command more than - once in a connection. - - - - - - - - - -Crispin Standards Track [Page 18] - -RFC 2060 IMAP4rev1 December 1996 - - - A capability name which begins with "AUTH=" indicates that the - server supports that particular authentication mechanism. All - such names are, by definition, part of this specification. For - example, the authorization capability for an experimental - "blurdybloop" authenticator would be "AUTH=XBLURDYBLOOP" and not - "XAUTH=BLURDYBLOOP" or "XAUTH=XBLURDYBLOOP". - - Other capability names refer to extensions, revisions, or - amendments to this specification. See the documentation of the - CAPABILITY response for additional information. No capabilities, - beyond the base IMAP4rev1 set defined in this specification, are - enabled without explicit client action to invoke the capability. - - See the section entitled "Client Commands - - Experimental/Expansion" for information about the form of site or - implementation-specific capabilities. - - Example: C: abcd CAPABILITY - S: * CAPABILITY IMAP4rev1 AUTH=KERBEROS_V4 - S: abcd OK CAPABILITY completed - -6.1.2. NOOP Command - - Arguments: none - - Responses: no specific responses for this command (but see below) - - Result: OK - noop completed - BAD - command unknown or arguments invalid - - The NOOP command always succeeds. It does nothing. - - Since any command can return a status update as untagged data, the - NOOP command can be used as a periodic poll for new messages or - message status updates during a period of inactivity. The NOOP - command can also be used to reset any inactivity autologout timer - on the server. - - Example: C: a002 NOOP - S: a002 OK NOOP completed - . . . - C: a047 NOOP - S: * 22 EXPUNGE - S: * 23 EXISTS - S: * 3 RECENT - S: * 14 FETCH (FLAGS (\Seen \Deleted)) - S: a047 OK NOOP completed - - - - -Crispin Standards Track [Page 19] - -RFC 2060 IMAP4rev1 December 1996 - - -6.1.3. LOGOUT Command - - Arguments: none - - Responses: REQUIRED untagged response: BYE - - Result: OK - logout completed - BAD - command unknown or arguments invalid - - The LOGOUT command informs the server that the client is done with - the connection. The server MUST send a BYE untagged response - before the (tagged) OK response, and then close the network - connection. - - Example: C: A023 LOGOUT - S: * BYE IMAP4rev1 Server logging out - S: A023 OK LOGOUT completed - (Server and client then close the connection) - -6.2. Client Commands - Non-Authenticated State - - In non-authenticated state, the AUTHENTICATE or LOGIN command - establishes authentication and enter authenticated state. The - AUTHENTICATE command provides a general mechanism for a variety of - authentication techniques, whereas the LOGIN command uses the - traditional user name and plaintext password pair. - - Server implementations MAY allow non-authenticated access to certain - mailboxes. The convention is to use a LOGIN command with the userid - "anonymous". A password is REQUIRED. It is implementation-dependent - what requirements, if any, are placed on the password and what access - restrictions are placed on anonymous users. - - Once authenticated (including as anonymous), it is not possible to - re-enter non-authenticated state. - - In addition to the universal commands (CAPABILITY, NOOP, and LOGOUT), - the following commands are valid in non-authenticated state: - AUTHENTICATE and LOGIN. - - - - - - - - - - - - -Crispin Standards Track [Page 20] - -RFC 2060 IMAP4rev1 December 1996 - - -6.2.1. AUTHENTICATE Command - - Arguments: authentication mechanism name - - Responses: continuation data can be requested - - Result: OK - authenticate completed, now in authenticated state - NO - authenticate failure: unsupported authentication - mechanism, credentials rejected - BAD - command unknown or arguments invalid, - authentication exchange cancelled - - The AUTHENTICATE command indicates an authentication mechanism, - such as described in [IMAP-AUTH], to the server. If the server - supports the requested authentication mechanism, it performs an - authentication protocol exchange to authenticate and identify the - client. It MAY also negotiate an OPTIONAL protection mechanism - for subsequent protocol interactions. If the requested - authentication mechanism is not supported, the server SHOULD - reject the AUTHENTICATE command by sending a tagged NO response. - - The authentication protocol exchange consists of a series of - server challenges and client answers that are specific to the - authentication mechanism. A server challenge consists of a - command continuation request response with the "+" token followed - by a BASE64 encoded string. The client answer consists of a line - consisting of a BASE64 encoded string. If the client wishes to - cancel an authentication exchange, it issues a line with a single - "*". If the server receives such an answer, it MUST reject the - AUTHENTICATE command by sending a tagged BAD response. - - A protection mechanism provides integrity and privacy protection - to the connection. If a protection mechanism is negotiated, it is - applied to all subsequent data sent over the connection. The - protection mechanism takes effect immediately following the CRLF - that concludes the authentication exchange for the client, and the - CRLF of the tagged OK response for the server. Once the - protection mechanism is in effect, the stream of command and - response octets is processed into buffers of ciphertext. Each - buffer is transferred over the connection as a stream of octets - prepended with a four octet field in network byte order that - represents the length of the following data. The maximum - ciphertext buffer length is defined by the protection mechanism. - - Authentication mechanisms are OPTIONAL. Protection mechanisms are - also OPTIONAL; an authentication mechanism MAY be implemented - without any protection mechanism. If an AUTHENTICATE command - fails with a NO response, the client MAY try another - - - -Crispin Standards Track [Page 21] - -RFC 2060 IMAP4rev1 December 1996 - - - authentication mechanism by issuing another AUTHENTICATE command, - or MAY attempt to authenticate by using the LOGIN command. In - other words, the client MAY request authentication types in - decreasing order of preference, with the LOGIN command as a last - resort. - - Example: S: * OK KerberosV4 IMAP4rev1 Server - C: A001 AUTHENTICATE KERBEROS_V4 - S: + AmFYig== - C: BAcAQU5EUkVXLkNNVS5FRFUAOCAsho84kLN3/IJmrMG+25a4DT - +nZImJjnTNHJUtxAA+o0KPKfHEcAFs9a3CL5Oebe/ydHJUwYFd - WwuQ1MWiy6IesKvjL5rL9WjXUb9MwT9bpObYLGOKi1Qh - S: + or//EoAADZI= - C: DiAF5A4gA+oOIALuBkAAmw== - S: A001 OK Kerberos V4 authentication successful - - Note: the line breaks in the first client answer are for editorial - clarity and are not in real authenticators. - -6.2.2. LOGIN Command - - Arguments: user name - password - - Responses: no specific responses for this command - - Result: OK - login completed, now in authenticated state - NO - login failure: user name or password rejected - BAD - command unknown or arguments invalid - - The LOGIN command identifies the client to the server and carries - the plaintext password authenticating this user. - - Example: C: a001 LOGIN SMITH SESAME - S: a001 OK LOGIN completed - -6.3. Client Commands - Authenticated State - - In authenticated state, commands that manipulate mailboxes as atomic - entities are permitted. Of these commands, the SELECT and EXAMINE - commands will select a mailbox for access and enter selected state. - - In addition to the universal commands (CAPABILITY, NOOP, and LOGOUT), - the following commands are valid in authenticated state: SELECT, - EXAMINE, CREATE, DELETE, RENAME, SUBSCRIBE, UNSUBSCRIBE, LIST, LSUB, - STATUS, and APPEND. - - - - - -Crispin Standards Track [Page 22] - -RFC 2060 IMAP4rev1 December 1996 - - -6.3.1. SELECT Command - - Arguments: mailbox name - - Responses: REQUIRED untagged responses: FLAGS, EXISTS, RECENT - OPTIONAL OK untagged responses: UNSEEN, PERMANENTFLAGS - - Result: OK - select completed, now in selected state - NO - select failure, now in authenticated state: no - such mailbox, can't access mailbox - BAD - command unknown or arguments invalid - - The SELECT command selects a mailbox so that messages in the - mailbox can be accessed. Before returning an OK to the client, - the server MUST send the following untagged data to the client: - - FLAGS Defined flags in the mailbox. See the description - of the FLAGS response for more detail. - - <n> EXISTS The number of messages in the mailbox. See the - description of the EXISTS response for more detail. - - <n> RECENT The number of messages with the \Recent flag set. - See the description of the RECENT response for more - detail. - - OK [UIDVALIDITY <n>] - The unique identifier validity value. See the - description of the UID command for more detail. - - to define the initial state of the mailbox at the client. - - The server SHOULD also send an UNSEEN response code in an OK - untagged response, indicating the message sequence number of the - first unseen message in the mailbox. - - If the client can not change the permanent state of one or more of - the flags listed in the FLAGS untagged response, the server SHOULD - send a PERMANENTFLAGS response code in an OK untagged response, - listing the flags that the client can change permanently. - - Only one mailbox can be selected at a time in a connection; - simultaneous access to multiple mailboxes requires multiple - connections. The SELECT command automatically deselects any - currently selected mailbox before attempting the new selection. - Consequently, if a mailbox is selected and a SELECT command that - fails is attempted, no mailbox is selected. - - - - -Crispin Standards Track [Page 23] - -RFC 2060 IMAP4rev1 December 1996 - - - If the client is permitted to modify the mailbox, the server - SHOULD prefix the text of the tagged OK response with the - "[READ-WRITE]" response code. - - If the client is not permitted to modify the mailbox but is - permitted read access, the mailbox is selected as read-only, and - the server MUST prefix the text of the tagged OK response to - SELECT with the "[READ-ONLY]" response code. Read-only access - through SELECT differs from the EXAMINE command in that certain - read-only mailboxes MAY permit the change of permanent state on a - per-user (as opposed to global) basis. Netnews messages marked in - a server-based .newsrc file are an example of such per-user - permanent state that can be modified with read-only mailboxes. - - Example: C: A142 SELECT INBOX - S: * 172 EXISTS - S: * 1 RECENT - S: * OK [UNSEEN 12] Message 12 is first unseen - S: * OK [UIDVALIDITY 3857529045] UIDs valid - S: * FLAGS (\Answered \Flagged \Deleted \Seen \Draft) - S: * OK [PERMANENTFLAGS (\Deleted \Seen \*)] Limited - S: A142 OK [READ-WRITE] SELECT completed - -6.3.2. EXAMINE Command - - Arguments: mailbox name - - Responses: REQUIRED untagged responses: FLAGS, EXISTS, RECENT - OPTIONAL OK untagged responses: UNSEEN, PERMANENTFLAGS - - Result: OK - examine completed, now in selected state - NO - examine failure, now in authenticated state: no - such mailbox, can't access mailbox - BAD - command unknown or arguments invalid - - The EXAMINE command is identical to SELECT and returns the same - output; however, the selected mailbox is identified as read-only. - No changes to the permanent state of the mailbox, including - per-user state, are permitted. - - - - - - - - - - - - -Crispin Standards Track [Page 24] - -RFC 2060 IMAP4rev1 December 1996 - - - The text of the tagged OK response to the EXAMINE command MUST - begin with the "[READ-ONLY]" response code. - - Example: C: A932 EXAMINE blurdybloop - S: * 17 EXISTS - S: * 2 RECENT - S: * OK [UNSEEN 8] Message 8 is first unseen - S: * OK [UIDVALIDITY 3857529045] UIDs valid - S: * FLAGS (\Answered \Flagged \Deleted \Seen \Draft) - S: * OK [PERMANENTFLAGS ()] No permanent flags permitted - S: A932 OK [READ-ONLY] EXAMINE completed - -6.3.3. CREATE Command - - Arguments: mailbox name - - Responses: no specific responses for this command - - Result: OK - create completed - NO - create failure: can't create mailbox with that name - BAD - command unknown or arguments invalid - - The CREATE command creates a mailbox with the given name. An OK - response is returned only if a new mailbox with that name has been - created. It is an error to attempt to create INBOX or a mailbox - with a name that refers to an extant mailbox. Any error in - creation will return a tagged NO response. - - If the mailbox name is suffixed with the server's hierarchy - separator character (as returned from the server by a LIST - command), this is a declaration that the client intends to create - mailbox names under this name in the hierarchy. Server - implementations that do not require this declaration MUST ignore - it. - - If the server's hierarchy separator character appears elsewhere in - the name, the server SHOULD create any superior hierarchical names - that are needed for the CREATE command to complete successfully. - In other words, an attempt to create "foo/bar/zap" on a server in - which "/" is the hierarchy separator character SHOULD create foo/ - and foo/bar/ if they do not already exist. - - If a new mailbox is created with the same name as a mailbox which - was deleted, its unique identifiers MUST be greater than any - unique identifiers used in the previous incarnation of the mailbox - UNLESS the new incarnation has a different unique identifier - validity value. See the description of the UID command for more - detail. - - - -Crispin Standards Track [Page 25] - -RFC 2060 IMAP4rev1 December 1996 - - - Example: C: A003 CREATE owatagusiam/ - S: A003 OK CREATE completed - C: A004 CREATE owatagusiam/blurdybloop - S: A004 OK CREATE completed - - Note: the interpretation of this example depends on whether "/" - was returned as the hierarchy separator from LIST. If "/" is the - hierarchy separator, a new level of hierarchy named "owatagusiam" - with a member called "blurdybloop" is created. Otherwise, two - mailboxes at the same hierarchy level are created. - -6.3.4. DELETE Command - - Arguments: mailbox name - - Responses: no specific responses for this command - - Result: OK - delete completed - NO - delete failure: can't delete mailbox with that name - BAD - command unknown or arguments invalid - - The DELETE command permanently removes the mailbox with the given - name. A tagged OK response is returned only if the mailbox has - been deleted. It is an error to attempt to delete INBOX or a - mailbox name that does not exist. - - The DELETE command MUST NOT remove inferior hierarchical names. - For example, if a mailbox "foo" has an inferior "foo.bar" - (assuming "." is the hierarchy delimiter character), removing - "foo" MUST NOT remove "foo.bar". It is an error to attempt to - delete a name that has inferior hierarchical names and also has - the \Noselect mailbox name attribute (see the description of the - LIST response for more details). - - It is permitted to delete a name that has inferior hierarchical - names and does not have the \Noselect mailbox name attribute. In - this case, all messages in that mailbox are removed, and the name - will acquire the \Noselect mailbox name attribute. - - The value of the highest-used unique identifier of the deleted - mailbox MUST be preserved so that a new mailbox created with the - same name will not reuse the identifiers of the former - incarnation, UNLESS the new incarnation has a different unique - identifier validity value. See the description of the UID command - for more detail. - - - - - - -Crispin Standards Track [Page 26] - -RFC 2060 IMAP4rev1 December 1996 - - - Examples: C: A682 LIST "" * - S: * LIST () "/" blurdybloop - S: * LIST (\Noselect) "/" foo - S: * LIST () "/" foo/bar - S: A682 OK LIST completed - C: A683 DELETE blurdybloop - S: A683 OK DELETE completed - C: A684 DELETE foo - S: A684 NO Name "foo" has inferior hierarchical names - C: A685 DELETE foo/bar - S: A685 OK DELETE Completed - C: A686 LIST "" * - S: * LIST (\Noselect) "/" foo - S: A686 OK LIST completed - C: A687 DELETE foo - S: A687 OK DELETE Completed - - - C: A82 LIST "" * - S: * LIST () "." blurdybloop - S: * LIST () "." foo - S: * LIST () "." foo.bar - S: A82 OK LIST completed - C: A83 DELETE blurdybloop - S: A83 OK DELETE completed - C: A84 DELETE foo - S: A84 OK DELETE Completed - C: A85 LIST "" * - S: * LIST () "." foo.bar - S: A85 OK LIST completed - C: A86 LIST "" % - S: * LIST (\Noselect) "." foo - S: A86 OK LIST completed - -6.3.5. RENAME Command - - Arguments: existing mailbox name - new mailbox name - - Responses: no specific responses for this command - - Result: OK - rename completed - NO - rename failure: can't rename mailbox with that name, - can't rename to mailbox with that name - BAD - command unknown or arguments invalid - - The RENAME command changes the name of a mailbox. A tagged OK - response is returned only if the mailbox has been renamed. It is - - - -Crispin Standards Track [Page 27] - -RFC 2060 IMAP4rev1 December 1996 - - - an error to attempt to rename from a mailbox name that does not - exist or to a mailbox name that already exists. Any error in - renaming will return a tagged NO response. - - If the name has inferior hierarchical names, then the inferior - hierarchical names MUST also be renamed. For example, a rename of - "foo" to "zap" will rename "foo/bar" (assuming "/" is the - hierarchy delimiter character) to "zap/bar". - - The value of the highest-used unique identifier of the old mailbox - name MUST be preserved so that a new mailbox created with the same - name will not reuse the identifiers of the former incarnation, - UNLESS the new incarnation has a different unique identifier - validity value. See the description of the UID command for more - detail. - - Renaming INBOX is permitted, and has special behavior. It moves - all messages in INBOX to a new mailbox with the given name, - leaving INBOX empty. If the server implementation supports - inferior hierarchical names of INBOX, these are unaffected by a - rename of INBOX. - - Examples: C: A682 LIST "" * - S: * LIST () "/" blurdybloop - S: * LIST (\Noselect) "/" foo - S: * LIST () "/" foo/bar - S: A682 OK LIST completed - C: A683 RENAME blurdybloop sarasoop - S: A683 OK RENAME completed - C: A684 RENAME foo zowie - S: A684 OK RENAME Completed - C: A685 LIST "" * - S: * LIST () "/" sarasoop - S: * LIST (\Noselect) "/" zowie - S: * LIST () "/" zowie/bar - S: A685 OK LIST completed - - - - - - - - - - - - - - - -Crispin Standards Track [Page 28] - -RFC 2060 IMAP4rev1 December 1996 - - - C: Z432 LIST "" * - S: * LIST () "." INBOX - S: * LIST () "." INBOX.bar - S: Z432 OK LIST completed - C: Z433 RENAME INBOX old-mail - S: Z433 OK RENAME completed - C: Z434 LIST "" * - S: * LIST () "." INBOX - S: * LIST () "." INBOX.bar - S: * LIST () "." old-mail - S: Z434 OK LIST completed - -6.3.6. SUBSCRIBE Command - - Arguments: mailbox - - Responses: no specific responses for this command - - Result: OK - subscribe completed - NO - subscribe failure: can't subscribe to that name - BAD - command unknown or arguments invalid - - The SUBSCRIBE command adds the specified mailbox name to the - server's set of "active" or "subscribed" mailboxes as returned by - the LSUB command. This command returns a tagged OK response only - if the subscription is successful. - - A server MAY validate the mailbox argument to SUBSCRIBE to verify - that it exists. However, it MUST NOT unilaterally remove an - existing mailbox name from the subscription list even if a mailbox - by that name no longer exists. - - Note: this requirement is because some server sites may routinely - remove a mailbox with a well-known name (e.g. "system-alerts") - after its contents expire, with the intention of recreating it - when new contents are appropriate. - - Example: C: A002 SUBSCRIBE #news.comp.mail.mime - S: A002 OK SUBSCRIBE completed - - - - - - - - - - - - -Crispin Standards Track [Page 29] - -RFC 2060 IMAP4rev1 December 1996 - - -6.3.7. UNSUBSCRIBE Command - - Arguments: mailbox name - - Responses: no specific responses for this command - - Result: OK - unsubscribe completed - NO - unsubscribe failure: can't unsubscribe that name - BAD - command unknown or arguments invalid - - The UNSUBSCRIBE command removes the specified mailbox name from - the server's set of "active" or "subscribed" mailboxes as returned - by the LSUB command. This command returns a tagged OK response - only if the unsubscription is successful. - - Example: C: A002 UNSUBSCRIBE #news.comp.mail.mime - S: A002 OK UNSUBSCRIBE completed - -6.3..8. LIST Command - - Arguments: reference name - mailbox name with possible wildcards - - Responses: untagged responses: LIST - - Result: OK - list completed - NO - list failure: can't list that reference or name - BAD - command unknown or arguments invalid - - The LIST command returns a subset of names from the complete set - of all names available to the client. Zero or more untagged LIST - replies are returned, containing the name attributes, hierarchy - delimiter, and name; see the description of the LIST reply for - more detail. - - The LIST command SHOULD return its data quickly, without undue - delay. For example, it SHOULD NOT go to excess trouble to - calculate \Marked or \Unmarked status or perform other processing; - if each name requires 1 second of processing, then a list of 1200 - names would take 20 minutes! - - An empty ("" string) reference name argument indicates that the - mailbox name is interpreted as by SELECT. The returned mailbox - names MUST match the supplied mailbox name pattern. A non-empty - reference name argument is the name of a mailbox or a level of - mailbox hierarchy, and indicates a context in which the mailbox - name is interpreted in an implementation-defined manner. - - - - -Crispin Standards Track [Page 30] - -RFC 2060 IMAP4rev1 December 1996 - - - An empty ("" string) mailbox name argument is a special request to - return the hierarchy delimiter and the root name of the name given - in the reference. The value returned as the root MAY be null if - the reference is non-rooted or is null. In all cases, the - hierarchy delimiter is returned. This permits a client to get the - hierarchy delimiter even when no mailboxes by that name currently - exist. - - The reference and mailbox name arguments are interpreted, in an - implementation-dependent fashion, into a canonical form that - represents an unambiguous left-to-right hierarchy. The returned - mailbox names will be in the interpreted form. - - Any part of the reference argument that is included in the - interpreted form SHOULD prefix the interpreted form. It SHOULD - also be in the same form as the reference name argument. This - rule permits the client to determine if the returned mailbox name - is in the context of the reference argument, or if something about - the mailbox argument overrode the reference argument. Without - this rule, the client would have to have knowledge of the server's - naming semantics including what characters are "breakouts" that - override a naming context. - - For example, here are some examples of how references and mailbox - names might be interpreted on a UNIX-based server: - - Reference Mailbox Name Interpretation - ------------ ------------ -------------- - ~smith/Mail/ foo.* ~smith/Mail/foo.* - archive/ % archive/% - #news. comp.mail.* #news.comp.mail.* - ~smith/Mail/ /usr/doc/foo /usr/doc/foo - archive/ ~fred/Mail/* ~fred/Mail/* - - The first three examples demonstrate interpretations in the - context of the reference argument. Note that "~smith/Mail" SHOULD - NOT be transformed into something like "/u2/users/smith/Mail", or - it would be impossible for the client to determine that the - interpretation was in the context of the reference. - - The character "*" is a wildcard, and matches zero or more - characters at this position. The character "%" is similar to "*", - but it does not match a hierarchy delimiter. If the "%" wildcard - is the last character of a mailbox name argument, matching levels - of hierarchy are also returned. If these levels of hierarchy are - not also selectable mailboxes, they are returned with the - \Noselect mailbox name attribute (see the description of the LIST - response for more details). - - - -Crispin Standards Track [Page 31] - -RFC 2060 IMAP4rev1 December 1996 - - - Server implementations are permitted to "hide" otherwise - accessible mailboxes from the wildcard characters, by preventing - certain characters or names from matching a wildcard in certain - situations. For example, a UNIX-based server might restrict the - interpretation of "*" so that an initial "/" character does not - match. - - The special name INBOX is included in the output from LIST, if - INBOX is supported by this server for this user and if the - uppercase string "INBOX" matches the interpreted reference and - mailbox name arguments with wildcards as described above. The - criteria for omitting INBOX is whether SELECT INBOX will return - failure; it is not relevant whether the user's real INBOX resides - on this or some other server. - - Example: C: A101 LIST "" "" - S: * LIST (\Noselect) "/" "" - S: A101 OK LIST Completed - C: A102 LIST #news.comp.mail.misc "" - S: * LIST (\Noselect) "." #news. - S: A102 OK LIST Completed - C: A103 LIST /usr/staff/jones "" - S: * LIST (\Noselect) "/" / - S: A103 OK LIST Completed - C: A202 LIST ~/Mail/ % - S: * LIST (\Noselect) "/" ~/Mail/foo - S: * LIST () "/" ~/Mail/meetings - S: A202 OK LIST completed - -6.3.9. LSUB Command - - Arguments: reference name - mailbox name with possible wildcards - - Responses: untagged responses: LSUB - - Result: OK - lsub completed - NO - lsub failure: can't list that reference or name - BAD - command unknown or arguments invalid - - The LSUB command returns a subset of names from the set of names - that the user has declared as being "active" or "subscribed". - Zero or more untagged LSUB replies are returned. The arguments to - LSUB are in the same form as those for LIST. - - A server MAY validate the subscribed names to see if they still - exist. If a name does not exist, it SHOULD be flagged with the - \Noselect attribute in the LSUB response. The server MUST NOT - - - -Crispin Standards Track [Page 32] - -RFC 2060 IMAP4rev1 December 1996 - - - unilaterally remove an existing mailbox name from the subscription - list even if a mailbox by that name no longer exists. - - Example: C: A002 LSUB "#news." "comp.mail.*" - S: * LSUB () "." #news.comp.mail.mime - S: * LSUB () "." #news.comp.mail.misc - S: A002 OK LSUB completed - -6.3.10. STATUS Command - - Arguments: mailbox name - status data item names - - Responses: untagged responses: STATUS - - Result: OK - status completed - NO - status failure: no status for that name - BAD - command unknown or arguments invalid - - The STATUS command requests the status of the indicated mailbox. - It does not change the currently selected mailbox, nor does it - affect the state of any messages in the queried mailbox (in - particular, STATUS MUST NOT cause messages to lose the \Recent - flag). - - The STATUS command provides an alternative to opening a second - IMAP4rev1 connection and doing an EXAMINE command on a mailbox to - query that mailbox's status without deselecting the current - mailbox in the first IMAP4rev1 connection. - - Unlike the LIST command, the STATUS command is not guaranteed to - be fast in its response. In some implementations, the server is - obliged to open the mailbox read-only internally to obtain certain - status information. Also unlike the LIST command, the STATUS - command does not accept wildcards. - - The currently defined status data items that can be requested are: - - MESSAGES The number of messages in the mailbox. - - RECENT The number of messages with the \Recent flag set. - - UIDNEXT The next UID value that will be assigned to a new - message in the mailbox. It is guaranteed that this - value will not change unless new messages are added - to the mailbox; and that it will change when new - messages are added even if those new messages are - subsequently expunged. - - - -Crispin Standards Track [Page 33] - -RFC 2060 IMAP4rev1 December 1996 - - - UIDVALIDITY The unique identifier validity value of the - mailbox. - - UNSEEN The number of messages which do not have the \Seen - flag set. - - - Example: C: A042 STATUS blurdybloop (UIDNEXT MESSAGES) - S: * STATUS blurdybloop (MESSAGES 231 UIDNEXT 44292) - S: A042 OK STATUS completed - -6.3.11. APPEND Command - - Arguments: mailbox name - OPTIONAL flag parenthesized list - OPTIONAL date/time string - message literal - - Responses: no specific responses for this command - - Result: OK - append completed - NO - append error: can't append to that mailbox, error - in flags or date/time or message text - BAD - command unknown or arguments invalid - - The APPEND command appends the literal argument as a new message - to the end of the specified destination mailbox. This argument - SHOULD be in the format of an [RFC-822] message. 8-bit characters - are permitted in the message. A server implementation that is - unable to preserve 8-bit data properly MUST be able to reversibly - convert 8-bit APPEND data to 7-bit using a [MIME-IMB] content - transfer encoding. - - Note: There MAY be exceptions, e.g. draft messages, in which - required [RFC-822] header lines are omitted in the message literal - argument to APPEND. The full implications of doing so MUST be - understood and carefully weighed. - - If a flag parenthesized list is specified, the flags SHOULD be set in - the resulting message; otherwise, the flag list of the resulting - message is set empty by default. - - If a date_time is specified, the internal date SHOULD be set in the - resulting message; otherwise, the internal date of the resulting - message is set to the current date and time by default. - - - - - - -Crispin Standards Track [Page 34] - -RFC 2060 IMAP4rev1 December 1996 - - - If the append is unsuccessful for any reason, the mailbox MUST be - restored to its state before the APPEND attempt; no partial appending - is permitted. - - If the destination mailbox does not exist, a server MUST return an - error, and MUST NOT automatically create the mailbox. Unless it is - certain that the destination mailbox can not be created, the server - MUST send the response code "[TRYCREATE]" as the prefix of the text - of the tagged NO response. This gives a hint to the client that it - can attempt a CREATE command and retry the APPEND if the CREATE is - successful. - - If the mailbox is currently selected, the normal new mail actions - SHOULD occur. Specifically, the server SHOULD notify the client - immediately via an untagged EXISTS response. If the server does not - do so, the client MAY issue a NOOP command (or failing that, a CHECK - command) after one or more APPEND commands. - - Example: C: A003 APPEND saved-messages (\Seen) {310} - C: Date: Mon, 7 Feb 1994 21:52:25 -0800 (PST) - C: From: Fred Foobar <foobar@Blurdybloop.COM> - C: Subject: afternoon meeting - C: To: mooch@owatagu.siam.edu - C: Message-Id: <B27397-0100000@Blurdybloop.COM> - C: MIME-Version: 1.0 - C: Content-Type: TEXT/PLAIN; CHARSET=US-ASCII - C: - C: Hello Joe, do you think we can meet at 3:30 tomorrow? - C: - S: A003 OK APPEND completed - - Note: the APPEND command is not used for message delivery, because - it does not provide a mechanism to transfer [SMTP] envelope - information. - -6.4. Client Commands - Selected State - - In selected state, commands that manipulate messages in a mailbox are - permitted. - - In addition to the universal commands (CAPABILITY, NOOP, and LOGOUT), - and the authenticated state commands (SELECT, EXAMINE, CREATE, - DELETE, RENAME, SUBSCRIBE, UNSUBSCRIBE, LIST, LSUB, STATUS, and - APPEND), the following commands are valid in the selected state: - CHECK, CLOSE, EXPUNGE, SEARCH, FETCH, STORE, COPY, and UID. - - - - - - -Crispin Standards Track [Page 35] - -RFC 2060 IMAP4rev1 December 1996 - - -6.4.1. CHECK Command - - Arguments: none - - Responses: no specific responses for this command - - Result: OK - check completed - BAD - command unknown or arguments invalid - - The CHECK command requests a checkpoint of the currently selected - mailbox. A checkpoint refers to any implementation-dependent - housekeeping associated with the mailbox (e.g. resolving the - server's in-memory state of the mailbox with the state on its - disk) that is not normally executed as part of each command. A - checkpoint MAY take a non-instantaneous amount of real time to - complete. If a server implementation has no such housekeeping - considerations, CHECK is equivalent to NOOP. - - There is no guarantee that an EXISTS untagged response will happen - as a result of CHECK. NOOP, not CHECK, SHOULD be used for new - mail polling. - - Example: C: FXXZ CHECK - S: FXXZ OK CHECK Completed - -6.4.2. CLOSE Command - - Arguments: none - - Responses: no specific responses for this command - - Result: OK - close completed, now in authenticated state - NO - close failure: no mailbox selected - BAD - command unknown or arguments invalid - - The CLOSE command permanently removes from the currently selected - mailbox all messages that have the \Deleted flag set, and returns - to authenticated state from selected state. No untagged EXPUNGE - responses are sent. - - No messages are removed, and no error is given, if the mailbox is - selected by an EXAMINE command or is otherwise selected read-only. - - Even if a mailbox is selected, a SELECT, EXAMINE, or LOGOUT - command MAY be issued without previously issuing a CLOSE command. - The SELECT, EXAMINE, and LOGOUT commands implicitly close the - currently selected mailbox without doing an expunge. However, - when many messages are deleted, a CLOSE-LOGOUT or CLOSE-SELECT - - - -Crispin Standards Track [Page 36] - -RFC 2060 IMAP4rev1 December 1996 - - - sequence is considerably faster than an EXPUNGE-LOGOUT or - EXPUNGE-SELECT because no untagged EXPUNGE responses (which the - client would probably ignore) are sent. - - Example: C: A341 CLOSE - S: A341 OK CLOSE completed - -6.4.3. EXPUNGE Command - - Arguments: none - - Responses: untagged responses: EXPUNGE - - Result: OK - expunge completed - NO - expunge failure: can't expunge (e.g. permission - denied) - BAD - command unknown or arguments invalid - - The EXPUNGE command permanently removes from the currently - selected mailbox all messages that have the \Deleted flag set. - Before returning an OK to the client, an untagged EXPUNGE response - is sent for each message that is removed. - - Example: C: A202 EXPUNGE - S: * 3 EXPUNGE - S: * 3 EXPUNGE - S: * 5 EXPUNGE - S: * 8 EXPUNGE - S: A202 OK EXPUNGE completed - - Note: in this example, messages 3, 4, 7, and 11 had the - \Deleted flag set. See the description of the EXPUNGE - response for further explanation. - -6.4.4. SEARCH Command - - Arguments: OPTIONAL [CHARSET] specification - searching criteria (one or more) - - Responses: REQUIRED untagged response: SEARCH - - Result: OK - search completed - NO - search error: can't search that [CHARSET] or - criteria - BAD - command unknown or arguments invalid - - - - - - -Crispin Standards Track [Page 37] - -RFC 2060 IMAP4rev1 December 1996 - - - The SEARCH command searches the mailbox for messages that match - the given searching criteria. Searching criteria consist of one - or more search keys. The untagged SEARCH response from the server - contains a listing of message sequence numbers corresponding to - those messages that match the searching criteria. - - When multiple keys are specified, the result is the intersection - (AND function) of all the messages that match those keys. For - example, the criteria DELETED FROM "SMITH" SINCE 1-Feb-1994 refers - to all deleted messages from Smith that were placed in the mailbox - since February 1, 1994. A search key can also be a parenthesized - list of one or more search keys (e.g. for use with the OR and NOT - keys). - - Server implementations MAY exclude [MIME-IMB] body parts with - terminal content media types other than TEXT and MESSAGE from - consideration in SEARCH matching. - - The OPTIONAL [CHARSET] specification consists of the word - "CHARSET" followed by a registered [CHARSET]. It indicates the - [CHARSET] of the strings that appear in the search criteria. - [MIME-IMB] content transfer encodings, and [MIME-HDRS] strings in - [RFC-822]/[MIME-IMB] headers, MUST be decoded before comparing - text in a [CHARSET] other than US-ASCII. US-ASCII MUST be - supported; other [CHARSET]s MAY be supported. If the server does - not support the specified [CHARSET], it MUST return a tagged NO - response (not a BAD). - - In all search keys that use strings, a message matches the key if - the string is a substring of the field. The matching is case- - insensitive. - - The defined search keys are as follows. Refer to the Formal - Syntax section for the precise syntactic definitions of the - arguments. - - <message set> Messages with message sequence numbers - corresponding to the specified message sequence - number set - - ALL All messages in the mailbox; the default initial - key for ANDing. - - ANSWERED Messages with the \Answered flag set. - - BCC <string> Messages that contain the specified string in the - envelope structure's BCC field. - - - - -Crispin Standards Track [Page 38] - -RFC 2060 IMAP4rev1 December 1996 - - - BEFORE <date> Messages whose internal date is earlier than the - specified date. - - BODY <string> Messages that contain the specified string in the - body of the message. - - CC <string> Messages that contain the specified string in the - envelope structure's CC field. - - DELETED Messages with the \Deleted flag set. - - DRAFT Messages with the \Draft flag set. - - FLAGGED Messages with the \Flagged flag set. - - FROM <string> Messages that contain the specified string in the - envelope structure's FROM field. - - HEADER <field-name> <string> - Messages that have a header with the specified - field-name (as defined in [RFC-822]) and that - contains the specified string in the [RFC-822] - field-body. - - KEYWORD <flag> Messages with the specified keyword set. - - LARGER <n> Messages with an [RFC-822] size larger than the - specified number of octets. - - NEW Messages that have the \Recent flag set but not the - \Seen flag. This is functionally equivalent to - "(RECENT UNSEEN)". - - NOT <search-key> - Messages that do not match the specified search - key. - - OLD Messages that do not have the \Recent flag set. - This is functionally equivalent to "NOT RECENT" (as - opposed to "NOT NEW"). - - ON <date> Messages whose internal date is within the - specified date. - - OR <search-key1> <search-key2> - Messages that match either search key. - - RECENT Messages that have the \Recent flag set. - - - -Crispin Standards Track [Page 39] - -RFC 2060 IMAP4rev1 December 1996 - - - SEEN Messages that have the \Seen flag set. - - SENTBEFORE <date> - Messages whose [RFC-822] Date: header is earlier - than the specified date. - - SENTON <date> Messages whose [RFC-822] Date: header is within the - specified date. - - SENTSINCE <date> - Messages whose [RFC-822] Date: header is within or - later than the specified date. - - SINCE <date> Messages whose internal date is within or later - than the specified date. - - SMALLER <n> Messages with an [RFC-822] size smaller than the - specified number of octets. - - SUBJECT <string> - Messages that contain the specified string in the - envelope structure's SUBJECT field. - - TEXT <string> Messages that contain the specified string in the - header or body of the message. - - TO <string> Messages that contain the specified string in the - envelope structure's TO field. - - UID <message set> - Messages with unique identifiers corresponding to - the specified unique identifier set. - - UNANSWERED Messages that do not have the \Answered flag set. - - UNDELETED Messages that do not have the \Deleted flag set. - - UNDRAFT Messages that do not have the \Draft flag set. - - UNFLAGGED Messages that do not have the \Flagged flag set. - - UNKEYWORD <flag> - Messages that do not have the specified keyword - set. - - UNSEEN Messages that do not have the \Seen flag set. - - - - - -Crispin Standards Track [Page 40] - -RFC 2060 IMAP4rev1 December 1996 - - - Example: C: A282 SEARCH FLAGGED SINCE 1-Feb-1994 NOT FROM "Smith" - S: * SEARCH 2 84 882 - S: A282 OK SEARCH completed - -6.4.5. FETCH Command - - Arguments: message set - message data item names - - Responses: untagged responses: FETCH - - Result: OK - fetch completed - NO - fetch error: can't fetch that data - BAD - command unknown or arguments invalid - - The FETCH command retrieves data associated with a message in the - mailbox. The data items to be fetched can be either a single atom - or a parenthesized list. - - The currently defined data items that can be fetched are: - - ALL Macro equivalent to: (FLAGS INTERNALDATE - RFC822.SIZE ENVELOPE) - - BODY Non-extensible form of BODYSTRUCTURE. - - BODY[<section>]<<partial>> - The text of a particular body section. The section - specification is a set of zero or more part - specifiers delimited by periods. A part specifier - is either a part number or one of the following: - HEADER, HEADER.FIELDS, HEADER.FIELDS.NOT, MIME, and - TEXT. An empty section specification refers to the - entire message, including the header. - - Every message has at least one part number. - Non-[MIME-IMB] messages, and non-multipart - [MIME-IMB] messages with no encapsulated message, - only have a part 1. - - Multipart messages are assigned consecutive part - numbers, as they occur in the message. If a - particular part is of type message or multipart, - its parts MUST be indicated by a period followed by - the part number within that nested multipart part. - - - - - - -Crispin Standards Track [Page 41] - -RFC 2060 IMAP4rev1 December 1996 - - - A part of type MESSAGE/RFC822 also has nested part - numbers, referring to parts of the MESSAGE part's - body. - - The HEADER, HEADER.FIELDS, HEADER.FIELDS.NOT, and - TEXT part specifiers can be the sole part specifier - or can be prefixed by one or more numeric part - specifiers, provided that the numeric part - specifier refers to a part of type MESSAGE/RFC822. - The MIME part specifier MUST be prefixed by one or - more numeric part specifiers. - - The HEADER, HEADER.FIELDS, and HEADER.FIELDS.NOT - part specifiers refer to the [RFC-822] header of - the message or of an encapsulated [MIME-IMT] - MESSAGE/RFC822 message. HEADER.FIELDS and - HEADER.FIELDS.NOT are followed by a list of - field-name (as defined in [RFC-822]) names, and - return a subset of the header. The subset returned - by HEADER.FIELDS contains only those header fields - with a field-name that matches one of the names in - the list; similarly, the subset returned by - HEADER.FIELDS.NOT contains only the header fields - with a non-matching field-name. The field-matching - is case-insensitive but otherwise exact. In all - cases, the delimiting blank line between the header - and the body is always included. - - The MIME part specifier refers to the [MIME-IMB] - header for this part. - - The TEXT part specifier refers to the text body of - the message, omitting the [RFC-822] header. - - - - - - - - - - - - - - - - - - -Crispin Standards Track [Page 42] - -RFC 2060 IMAP4rev1 December 1996 - - - Here is an example of a complex message - with some of its part specifiers: - - HEADER ([RFC-822] header of the message) - TEXT MULTIPART/MIXED - 1 TEXT/PLAIN - 2 APPLICATION/OCTET-STREAM - 3 MESSAGE/RFC822 - 3.HEADER ([RFC-822] header of the message) - 3.TEXT ([RFC-822] text body of the message) - 3.1 TEXT/PLAIN - 3.2 APPLICATION/OCTET-STREAM - 4 MULTIPART/MIXED - 4.1 IMAGE/GIF - 4.1.MIME ([MIME-IMB] header for the IMAGE/GIF) - 4.2 MESSAGE/RFC822 - 4.2.HEADER ([RFC-822] header of the message) - 4.2.TEXT ([RFC-822] text body of the message) - 4.2.1 TEXT/PLAIN - 4.2.2 MULTIPART/ALTERNATIVE - 4.2.2.1 TEXT/PLAIN - 4.2.2.2 TEXT/RICHTEXT - - - It is possible to fetch a substring of the - designated text. This is done by appending an open - angle bracket ("<"), the octet position of the - first desired octet, a period, the maximum number - of octets desired, and a close angle bracket (">") - to the part specifier. If the starting octet is - beyond the end of the text, an empty string is - returned. - - Any partial fetch that attempts to read beyond the - end of the text is truncated as appropriate. A - partial fetch that starts at octet 0 is returned as - a partial fetch, even if this truncation happened. - - Note: this means that BODY[]<0.2048> of a - 1500-octet message will return BODY[]<0> - with a literal of size 1500, not BODY[]. - - Note: a substring fetch of a - HEADER.FIELDS or HEADER.FIELDS.NOT part - specifier is calculated after subsetting - the header. - - - - - -Crispin Standards Track [Page 43] - -RFC 2060 IMAP4rev1 December 1996 - - - The \Seen flag is implicitly set; if this causes - the flags to change they SHOULD be included as part - of the FETCH responses. - - BODY.PEEK[<section>]<<partial>> An alternate form of - BODY[<section>] that does not implicitly set the - \Seen flag. - - BODYSTRUCTURE The [MIME-IMB] body structure of the message. This - is computed by the server by parsing the [MIME-IMB] - header fields in the [RFC-822] header and - [MIME-IMB] headers. - - ENVELOPE The envelope structure of the message. This is - computed by the server by parsing the [RFC-822] - header into the component parts, defaulting various - fields as necessary. - - FAST Macro equivalent to: (FLAGS INTERNALDATE - RFC822.SIZE) - - FLAGS The flags that are set for this message. - - FULL Macro equivalent to: (FLAGS INTERNALDATE - RFC822.SIZE ENVELOPE BODY) - - INTERNALDATE The internal date of the message. - - RFC822 Functionally equivalent to BODY[], differing in the - syntax of the resulting untagged FETCH data (RFC822 - is returned). - - RFC822.HEADER Functionally equivalent to BODY.PEEK[HEADER], - differing in the syntax of the resulting untagged - FETCH data (RFC822.HEADER is returned). - - RFC822.SIZE The [RFC-822] size of the message. - - RFC822.TEXT Functionally equivalent to BODY[TEXT], differing in - the syntax of the resulting untagged FETCH data - (RFC822.TEXT is returned). - - UID The unique identifier for the message. - - - - - - - - -Crispin Standards Track [Page 44] - -RFC 2060 IMAP4rev1 December 1996 - - - Example: C: A654 FETCH 2:4 (FLAGS BODY[HEADER.FIELDS (DATE FROM)]) - S: * 2 FETCH .... - S: * 3 FETCH .... - S: * 4 FETCH .... - S: A654 OK FETCH completed - -6.4.6. STORE Command - - Arguments: message set - message data item name - value for message data item - - Responses: untagged responses: FETCH - - Result: OK - store completed - NO - store error: can't store that data - BAD - command unknown or arguments invalid - - The STORE command alters data associated with a message in the - mailbox. Normally, STORE will return the updated value of the - data with an untagged FETCH response. A suffix of ".SILENT" in - the data item name prevents the untagged FETCH, and the server - SHOULD assume that the client has determined the updated value - itself or does not care about the updated value. - - Note: regardless of whether or not the ".SILENT" suffix was - used, the server SHOULD send an untagged FETCH response if a - change to a message's flags from an external source is - observed. The intent is that the status of the flags is - determinate without a race condition. - - The currently defined data items that can be stored are: - - FLAGS <flag list> - Replace the flags for the message with the - argument. The new value of the flags are returned - as if a FETCH of those flags was done. - - FLAGS.SILENT <flag list> - Equivalent to FLAGS, but without returning a new - value. - - +FLAGS <flag list> - Add the argument to the flags for the message. The - new value of the flags are returned as if a FETCH - of those flags was done. - - - - - -Crispin Standards Track [Page 45] - -RFC 2060 IMAP4rev1 December 1996 - - - +FLAGS.SILENT <flag list> - Equivalent to +FLAGS, but without returning a new - value. - - -FLAGS <flag list> - Remove the argument from the flags for the message. - The new value of the flags are returned as if a - FETCH of those flags was done. - - -FLAGS.SILENT <flag list> - Equivalent to -FLAGS, but without returning a new - value. - - Example: C: A003 STORE 2:4 +FLAGS (\Deleted) - S: * 2 FETCH FLAGS (\Deleted \Seen) - S: * 3 FETCH FLAGS (\Deleted) - S: * 4 FETCH FLAGS (\Deleted \Flagged \Seen) - S: A003 OK STORE completed - -6.4.7. COPY Command - - Arguments: message set - mailbox name - - Responses: no specific responses for this command - - Result: OK - copy completed - NO - copy error: can't copy those messages or to that - name - BAD - command unknown or arguments invalid - - The COPY command copies the specified message(s) to the end of the - specified destination mailbox. The flags and internal date of the - message(s) SHOULD be preserved in the copy. - - If the destination mailbox does not exist, a server SHOULD return - an error. It SHOULD NOT automatically create the mailbox. Unless - it is certain that the destination mailbox can not be created, the - server MUST send the response code "[TRYCREATE]" as the prefix of - the text of the tagged NO response. This gives a hint to the - client that it can attempt a CREATE command and retry the COPY if - the CREATE is successful. - - - - - - - - - -Crispin Standards Track [Page 46] - -RFC 2060 IMAP4rev1 December 1996 - - - If the COPY command is unsuccessful for any reason, server - implementations MUST restore the destination mailbox to its state - before the COPY attempt. - - Example: C: A003 COPY 2:4 MEETING - S: A003 OK COPY completed - -6.4.8. UID Command - - Arguments: command name - command arguments - - Responses: untagged responses: FETCH, SEARCH - - Result: OK - UID command completed - NO - UID command error - BAD - command unknown or arguments invalid - - The UID command has two forms. In the first form, it takes as its - arguments a COPY, FETCH, or STORE command with arguments - appropriate for the associated command. However, the numbers in - the message set argument are unique identifiers instead of message - sequence numbers. - - In the second form, the UID command takes a SEARCH command with - SEARCH command arguments. The interpretation of the arguments is - the same as with SEARCH; however, the numbers returned in a SEARCH - response for a UID SEARCH command are unique identifiers instead - of message sequence numbers. For example, the command UID SEARCH - 1:100 UID 443:557 returns the unique identifiers corresponding to - the intersection of the message sequence number set 1:100 and the - UID set 443:557. - - Message set ranges are permitted; however, there is no guarantee - that unique identifiers be contiguous. A non-existent unique - identifier within a message set range is ignored without any error - message generated. - - The number after the "*" in an untagged FETCH response is always a - message sequence number, not a unique identifier, even for a UID - command response. However, server implementations MUST implicitly - include the UID message data item as part of any FETCH response - caused by a UID command, regardless of whether a UID was specified - as a message data item to the FETCH. - - - - - - - -Crispin Standards Track [Page 47] - -RFC 2060 IMAP4rev1 December 1996 - - - Example: C: A999 UID FETCH 4827313:4828442 FLAGS - S: * 23 FETCH (FLAGS (\Seen) UID 4827313) - S: * 24 FETCH (FLAGS (\Seen) UID 4827943) - S: * 25 FETCH (FLAGS (\Seen) UID 4828442) - S: A999 UID FETCH completed - -6.5. Client Commands - Experimental/Expansion - -6.5.1. X<atom> Command - - Arguments: implementation defined - - Responses: implementation defined - - Result: OK - command completed - NO - failure - BAD - command unknown or arguments invalid - - Any command prefixed with an X is an experimental command. - Commands which are not part of this specification, a standard or - standards-track revision of this specification, or an IESG- - approved experimental protocol, MUST use the X prefix. - - Any added untagged responses issued by an experimental command - MUST also be prefixed with an X. Server implementations MUST NOT - send any such untagged responses, unless the client requested it - by issuing the associated experimental command. - - Example: C: a441 CAPABILITY - S: * CAPABILITY IMAP4rev1 AUTH=KERBEROS_V4 XPIG-LATIN - S: a441 OK CAPABILITY completed - C: A442 XPIG-LATIN - S: * XPIG-LATIN ow-nay eaking-spay ig-pay atin-lay - S: A442 OK XPIG-LATIN ompleted-cay - -7. Server Responses - - Server responses are in three forms: status responses, server data, - and command continuation request. The information contained in a - server response, identified by "Contents:" in the response - descriptions below, is described by function, not by syntax. The - precise syntax of server responses is described in the Formal Syntax - section. - - The client MUST be prepared to accept any response at all times. - - - - - - -Crispin Standards Track [Page 48] - -RFC 2060 IMAP4rev1 December 1996 - - - Status responses can be tagged or untagged. Tagged status responses - indicate the completion result (OK, NO, or BAD status) of a client - command, and have a tag matching the command. - - Some status responses, and all server data, are untagged. An - untagged response is indicated by the token "*" instead of a tag. - Untagged status responses indicate server greeting, or server status - that does not indicate the completion of a command (for example, an - impending system shutdown alert). For historical reasons, untagged - server data responses are also called "unsolicited data", although - strictly speaking only unilateral server data is truly "unsolicited". - - Certain server data MUST be recorded by the client when it is - received; this is noted in the description of that data. Such data - conveys critical information which affects the interpretation of all - subsequent commands and responses (e.g. updates reflecting the - creation or destruction of messages). - - Other server data SHOULD be recorded for later reference; if the - client does not need to record the data, or if recording the data has - no obvious purpose (e.g. a SEARCH response when no SEARCH command is - in progress), the data SHOULD be ignored. - - An example of unilateral untagged server data occurs when the IMAP - connection is in selected state. In selected state, the server - checks the mailbox for new messages as part of command execution. - Normally, this is part of the execution of every command; hence, a - NOOP command suffices to check for new messages. If new messages are - found, the server sends untagged EXISTS and RECENT responses - reflecting the new size of the mailbox. Server implementations that - offer multiple simultaneous access to the same mailbox SHOULD also - send appropriate unilateral untagged FETCH and EXPUNGE responses if - another agent changes the state of any message flags or expunges any - messages. - - Command continuation request responses use the token "+" instead of a - tag. These responses are sent by the server to indicate acceptance - of an incomplete client command and readiness for the remainder of - the command. - -7.1. Server Responses - Status Responses - - Status responses are OK, NO, BAD, PREAUTH and BYE. OK, NO, and BAD - may be tagged or untagged. PREAUTH and BYE are always untagged. - - Status responses MAY include an OPTIONAL "response code". A response - code consists of data inside square brackets in the form of an atom, - possibly followed by a space and arguments. The response code - - - -Crispin Standards Track [Page 49] - -RFC 2060 IMAP4rev1 December 1996 - - - contains additional information or status codes for client software - beyond the OK/NO/BAD condition, and are defined when there is a - specific action that a client can take based upon the additional - information. - - The currently defined response codes are: - - ALERT The human-readable text contains a special alert - that MUST be presented to the user in a fashion - that calls the user's attention to the message. - - NEWNAME Followed by a mailbox name and a new mailbox name. - A SELECT or EXAMINE is failing because the target - mailbox name no longer exists because it was - renamed to the new mailbox name. This is a hint to - the client that the operation can succeed if the - SELECT or EXAMINE is reissued with the new mailbox - name. - - PARSE The human-readable text represents an error in - parsing the [RFC-822] header or [MIME-IMB] headers - of a message in the mailbox. - - PERMANENTFLAGS Followed by a parenthesized list of flags, - indicates which of the known flags that the client - can change permanently. Any flags that are in the - FLAGS untagged response, but not the PERMANENTFLAGS - list, can not be set permanently. If the client - attempts to STORE a flag that is not in the - PERMANENTFLAGS list, the server will either reject - it with a NO reply or store the state for the - remainder of the current session only. The - PERMANENTFLAGS list can also include the special - flag \*, which indicates that it is possible to - create new keywords by attempting to store those - flags in the mailbox. - - READ-ONLY The mailbox is selected read-only, or its access - while selected has changed from read-write to - read-only. - - READ-WRITE The mailbox is selected read-write, or its access - while selected has changed from read-only to - read-write. - - - - - - - -Crispin Standards Track [Page 50] - -RFC 2060 IMAP4rev1 December 1996 - - - TRYCREATE An APPEND or COPY attempt is failing because the - target mailbox does not exist (as opposed to some - other reason). This is a hint to the client that - the operation can succeed if the mailbox is first - created by the CREATE command. - - UIDVALIDITY Followed by a decimal number, indicates the unique - identifier validity value. - - UNSEEN Followed by a decimal number, indicates the number - of the first message without the \Seen flag set. - - Additional response codes defined by particular client or server - implementations SHOULD be prefixed with an "X" until they are - added to a revision of this protocol. Client implementations - SHOULD ignore response codes that they do not recognize. - -7.1.1. OK Response - - Contents: OPTIONAL response code - human-readable text - - The OK response indicates an information message from the server. - When tagged, it indicates successful completion of the associated - command. The human-readable text MAY be presented to the user as - an information message. The untagged form indicates an - information-only message; the nature of the information MAY be - indicated by a response code. - - The untagged form is also used as one of three possible greetings - at connection startup. It indicates that the connection is not - yet authenticated and that a LOGIN command is needed. - - Example: S: * OK IMAP4rev1 server ready - C: A001 LOGIN fred blurdybloop - S: * OK [ALERT] System shutdown in 10 minutes - S: A001 OK LOGIN Completed - -7.1.2. NO Response - - Contents: OPTIONAL response code - human-readable text - - The NO response indicates an operational error message from the - server. When tagged, it indicates unsuccessful completion of the - associated command. The untagged form indicates a warning; the - command can still complete successfully. The human-readable text - describes the condition. - - - -Crispin Standards Track [Page 51] - -RFC 2060 IMAP4rev1 December 1996 - - - Example: C: A222 COPY 1:2 owatagusiam - S: * NO Disk is 98% full, please delete unnecessary data - S: A222 OK COPY completed - C: A223 COPY 3:200 blurdybloop - S: * NO Disk is 98% full, please delete unnecessary data - S: * NO Disk is 99% full, please delete unnecessary data - S: A223 NO COPY failed: disk is full - -7.1.3. BAD Response - - Contents: OPTIONAL response code - human-readable text - - The BAD response indicates an error message from the server. When - tagged, it reports a protocol-level error in the client's command; - the tag indicates the command that caused the error. The untagged - form indicates a protocol-level error for which the associated - command can not be determined; it can also indicate an internal - server failure. The human-readable text describes the condition. - - Example: C: ...very long command line... - S: * BAD Command line too long - C: ...empty line... - S: * BAD Empty command line - C: A443 EXPUNGE - S: * BAD Disk crash, attempting salvage to a new disk! - S: * OK Salvage successful, no data lost - S: A443 OK Expunge completed - -7.1.4. PREAUTH Response - - Contents: OPTIONAL response code - human-readable text - - The PREAUTH response is always untagged, and is one of three - possible greetings at connection startup. It indicates that the - connection has already been authenticated by external means and - thus no LOGIN command is needed. - - Example: S: * PREAUTH IMAP4rev1 server logged in as Smith - -7.1.5. BYE Response - - Contents: OPTIONAL response code - human-readable text - - - - - - -Crispin Standards Track [Page 52] - -RFC 2060 IMAP4rev1 December 1996 - - - The BYE response is always untagged, and indicates that the server - is about to close the connection. The human-readable text MAY be - displayed to the user in a status report by the client. The BYE - response is sent under one of four conditions: - - 1) as part of a normal logout sequence. The server will close - the connection after sending the tagged OK response to the - LOGOUT command. - - 2) as a panic shutdown announcement. The server closes the - connection immediately. - - 3) as an announcement of an inactivity autologout. The server - closes the connection immediately. - - 4) as one of three possible greetings at connection startup, - indicating that the server is not willing to accept a - connection from this client. The server closes the - connection immediately. - - The difference between a BYE that occurs as part of a normal - LOGOUT sequence (the first case) and a BYE that occurs because of - a failure (the other three cases) is that the connection closes - immediately in the failure case. - - Example: S: * BYE Autologout; idle for too long - -7.2. Server Responses - Server and Mailbox Status - - These responses are always untagged. This is how server and mailbox - status data are transmitted from the server to the client. Many of - these responses typically result from a command with the same name. - -7.2.1. CAPABILITY Response - - Contents: capability listing - - The CAPABILITY response occurs as a result of a CAPABILITY - command. The capability listing contains a space-separated - listing of capability names that the server supports. The - capability listing MUST include the atom "IMAP4rev1". - - A capability name which begins with "AUTH=" indicates that the - server supports that particular authentication mechanism. - - - - - - - -Crispin Standards Track [Page 53] - -RFC 2060 IMAP4rev1 December 1996 - - - Other capability names indicate that the server supports an - extension, revision, or amendment to the IMAP4rev1 protocol. - Server responses MUST conform to this document until the client - issues a command that uses the associated capability. - - Capability names MUST either begin with "X" or be standard or - standards-track IMAP4rev1 extensions, revisions, or amendments - registered with IANA. A server MUST NOT offer unregistered or - non-standard capability names, unless such names are prefixed with - an "X". - - Client implementations SHOULD NOT require any capability name - other than "IMAP4rev1", and MUST ignore any unknown capability - names. - - Example: S: * CAPABILITY IMAP4rev1 AUTH=KERBEROS_V4 XPIG-LATIN - -7.2.2. LIST Response - - Contents: name attributes - hierarchy delimiter - name - - The LIST response occurs as a result of a LIST command. It - returns a single name that matches the LIST specification. There - can be multiple LIST responses for a single LIST command. - - Four name attributes are defined: - - \Noinferiors It is not possible for any child levels of - hierarchy to exist under this name; no child levels - exist now and none can be created in the future. - - \Noselect It is not possible to use this name as a selectable - mailbox. - - \Marked The mailbox has been marked "interesting" by the - server; the mailbox probably contains messages that - have been added since the last time the mailbox was - selected. - - \Unmarked The mailbox does not contain any additional - messages since the last time the mailbox was - selected. - - If it is not feasible for the server to determine whether the - mailbox is "interesting" or not, or if the name is a \Noselect - name, the server SHOULD NOT send either \Marked or \Unmarked. - - - -Crispin Standards Track [Page 54] - -RFC 2060 IMAP4rev1 December 1996 - - - The hierarchy delimiter is a character used to delimit levels of - hierarchy in a mailbox name. A client can use it to create child - mailboxes, and to search higher or lower levels of naming - hierarchy. All children of a top-level hierarchy node MUST use - the same separator character. A NIL hierarchy delimiter means - that no hierarchy exists; the name is a "flat" name. - - The name represents an unambiguous left-to-right hierarchy, and - MUST be valid for use as a reference in LIST and LSUB commands. - Unless \Noselect is indicated, the name MUST also be valid as an - argument for commands, such as SELECT, that accept mailbox - names. - - Example: S: * LIST (\Noselect) "/" ~/Mail/foo - -7.2.3. LSUB Response - - Contents: name attributes - hierarchy delimiter - name - - The LSUB response occurs as a result of an LSUB command. It - returns a single name that matches the LSUB specification. There - can be multiple LSUB responses for a single LSUB command. The - data is identical in format to the LIST response. - - Example: S: * LSUB () "." #news.comp.mail.misc - -7.2.4 STATUS Response - - Contents: name - status parenthesized list - - The STATUS response occurs as a result of an STATUS command. It - returns the mailbox name that matches the STATUS specification and - the requested mailbox status information. - - Example: S: * STATUS blurdybloop (MESSAGES 231 UIDNEXT 44292) - -7.2.5. SEARCH Response - - Contents: zero or more numbers - - - - - - - - - -Crispin Standards Track [Page 55] - -RFC 2060 IMAP4rev1 December 1996 - - - The SEARCH response occurs as a result of a SEARCH or UID SEARCH - command. The number(s) refer to those messages that match the - search criteria. For SEARCH, these are message sequence numbers; - for UID SEARCH, these are unique identifiers. Each number is - delimited by a space. - - Example: S: * SEARCH 2 3 6 - -7.2.6. FLAGS Response - - Contents: flag parenthesized list - - The FLAGS response occurs as a result of a SELECT or EXAMINE - command. The flag parenthesized list identifies the flags (at a - minimum, the system-defined flags) that are applicable for this - mailbox. Flags other than the system flags can also exist, - depending on server implementation. - - The update from the FLAGS response MUST be recorded by the client. - - Example: S: * FLAGS (\Answered \Flagged \Deleted \Seen \Draft) - -7.3. Server Responses - Mailbox Size - - These responses are always untagged. This is how changes in the size - of the mailbox are trasnmitted from the server to the client. - Immediately following the "*" token is a number that represents a - message count. - -7.3.1. EXISTS Response - - Contents: none - - The EXISTS response reports the number of messages in the mailbox. - This response occurs as a result of a SELECT or EXAMINE command, - and if the size of the mailbox changes (e.g. new mail). - - The update from the EXISTS response MUST be recorded by the - client. - - Example: S: * 23 EXISTS - - - - - - - - - - -Crispin Standards Track [Page 56] - -RFC 2060 IMAP4rev1 December 1996 - - -7.3.2. RECENT Response - - Contents: none - - The RECENT response reports the number of messages with the - \Recent flag set. This response occurs as a result of a SELECT or - EXAMINE command, and if the size of the mailbox changes (e.g. new - mail). - - Note: It is not guaranteed that the message sequence numbers of - recent messages will be a contiguous range of the highest n - messages in the mailbox (where n is the value reported by the - RECENT response). Examples of situations in which this is not - the case are: multiple clients having the same mailbox open - (the first session to be notified will see it as recent, others - will probably see it as non-recent), and when the mailbox is - re-ordered by a non-IMAP agent. - - The only reliable way to identify recent messages is to look at - message flags to see which have the \Recent flag set, or to do - a SEARCH RECENT. - - The update from the RECENT response MUST be recorded by the - client. - - Example: S: * 5 RECENT - -7.4. Server Responses - Message Status - - These responses are always untagged. This is how message data are - transmitted from the server to the client, often as a result of a - command with the same name. Immediately following the "*" token is a - number that represents a message sequence number. - -7.4.1. EXPUNGE Response - - Contents: none - - The EXPUNGE response reports that the specified message sequence - number has been permanently removed from the mailbox. The message - sequence number for each successive message in the mailbox is - immediately decremented by 1, and this decrement is reflected in - message sequence numbers in subsequent responses (including other - untagged EXPUNGE responses). - - As a result of the immediate decrement rule, message sequence - numbers that appear in a set of successive EXPUNGE responses - depend upon whether the messages are removed starting from lower - - - -Crispin Standards Track [Page 57] - -RFC 2060 IMAP4rev1 December 1996 - - - numbers to higher numbers, or from higher numbers to lower - numbers. For example, if the last 5 messages in a 9-message - mailbox are expunged; a "lower to higher" server will send five - untagged EXPUNGE responses for message sequence number 5, whereas - a "higher to lower server" will send successive untagged EXPUNGE - responses for message sequence numbers 9, 8, 7, 6, and 5. - - An EXPUNGE response MUST NOT be sent when no command is in - progress; nor while responding to a FETCH, STORE, or SEARCH - command. This rule is necessary to prevent a loss of - synchronization of message sequence numbers between client and - server. - - The update from the EXPUNGE response MUST be recorded by the - client. - - Example: S: * 44 EXPUNGE - -7.4.2. FETCH Response - - Contents: message data - - The FETCH response returns data about a message to the client. - The data are pairs of data item names and their values in - parentheses. This response occurs as the result of a FETCH or - STORE command, as well as by unilateral server decision (e.g. flag - updates). - - The current data items are: - - BODY A form of BODYSTRUCTURE without extension data. - - BODY[<section>]<<origin_octet>> - A string expressing the body contents of the - specified section. The string SHOULD be - interpreted by the client according to the content - transfer encoding, body type, and subtype. - - If the origin octet is specified, this string is a - substring of the entire body contents, starting at - that origin octet. This means that BODY[]<0> MAY - be truncated, but BODY[] is NEVER truncated. - - 8-bit textual data is permitted if a [CHARSET] - identifier is part of the body parameter - parenthesized list for this section. Note that - headers (part specifiers HEADER or MIME, or the - header portion of a MESSAGE/RFC822 part), MUST be - - - -Crispin Standards Track [Page 58] - -RFC 2060 IMAP4rev1 December 1996 - - - 7-bit; 8-bit characters are not permitted in - headers. Note also that the blank line at the end - of the header is always included in header data. - - Non-textual data such as binary data MUST be - transfer encoded into a textual form such as BASE64 - prior to being sent to the client. To derive the - original binary data, the client MUST decode the - transfer encoded string. - - BODYSTRUCTURE A parenthesized list that describes the [MIME-IMB] - body structure of a message. This is computed by - the server by parsing the [MIME-IMB] header fields, - defaulting various fields as necessary. - - For example, a simple text message of 48 lines and - 2279 octets can have a body structure of: ("TEXT" - "PLAIN" ("CHARSET" "US-ASCII") NIL NIL "7BIT" 2279 - 48) - - Multiple parts are indicated by parenthesis - nesting. Instead of a body type as the first - element of the parenthesized list there is a nested - body. The second element of the parenthesized list - is the multipart subtype (mixed, digest, parallel, - alternative, etc.). - - For example, a two part message consisting of a - text and a BASE645-encoded text attachment can have - a body structure of: (("TEXT" "PLAIN" ("CHARSET" - "US-ASCII") NIL NIL "7BIT" 1152 23)("TEXT" "PLAIN" - ("CHARSET" "US-ASCII" "NAME" "cc.diff") - "<960723163407.20117h@cac.washington.edu>" - "Compiler diff" "BASE64" 4554 73) "MIXED")) - - Extension data follows the multipart subtype. - Extension data is never returned with the BODY - fetch, but can be returned with a BODYSTRUCTURE - fetch. Extension data, if present, MUST be in the - defined order. - - The extension data of a multipart body part are in - the following order: - - body parameter parenthesized list - A parenthesized list of attribute/value pairs - [e.g. ("foo" "bar" "baz" "rag") where "bar" is - the value of "foo" and "rag" is the value of - - - -Crispin Standards Track [Page 59] - -RFC 2060 IMAP4rev1 December 1996 - - - "baz"] as defined in [MIME-IMB]. - - body disposition - A parenthesized list, consisting of a - disposition type string followed by a - parenthesized list of disposition - attribute/value pairs. The disposition type and - attribute names will be defined in a future - standards-track revision to [DISPOSITION]. - - body language - A string or parenthesized list giving the body - language value as defined in [LANGUAGE-TAGS]. - - Any following extension data are not yet defined in - this version of the protocol. Such extension data - can consist of zero or more NILs, strings, numbers, - or potentially nested parenthesized lists of such - data. Client implementations that do a - BODYSTRUCTURE fetch MUST be prepared to accept such - extension data. Server implementations MUST NOT - send such extension data until it has been defined - by a revision of this protocol. - - The basic fields of a non-multipart body part are - in the following order: - - body type - A string giving the content media type name as - defined in [MIME-IMB]. - - body subtype - A string giving the content subtype name as - defined in [MIME-IMB]. - - body parameter parenthesized list - A parenthesized list of attribute/value pairs - [e.g. ("foo" "bar" "baz" "rag") where "bar" is - the value of "foo" and "rag" is the value of - "baz"] as defined in [MIME-IMB]. - - body id - A string giving the content id as defined in - [MIME-IMB]. - - body description - A string giving the content description as - defined in [MIME-IMB]. - - - -Crispin Standards Track [Page 60] - -RFC 2060 IMAP4rev1 December 1996 - - - body encoding - A string giving the content transfer encoding as - defined in [MIME-IMB]. - - body size - A number giving the size of the body in octets. - Note that this size is the size in its transfer - encoding and not the resulting size after any - decoding. - - A body type of type MESSAGE and subtype RFC822 - contains, immediately after the basic fields, the - envelope structure, body structure, and size in - text lines of the encapsulated message. - - A body type of type TEXT contains, immediately - after the basic fields, the size of the body in - text lines. Note that this size is the size in its - content transfer encoding and not the resulting - size after any decoding. - - Extension data follows the basic fields and the - type-specific fields listed above. Extension data - is never returned with the BODY fetch, but can be - returned with a BODYSTRUCTURE fetch. Extension - data, if present, MUST be in the defined order. - - The extension data of a non-multipart body part are - in the following order: - - body MD5 - A string giving the body MD5 value as defined in - [MD5]. - - body disposition - A parenthesized list with the same content and - function as the body disposition for a multipart - body part. - - body language - A string or parenthesized list giving the body - language value as defined in [LANGUAGE-TAGS]. - - Any following extension data are not yet defined in - this version of the protocol, and would be as - described above under multipart extension data. - - - - - -Crispin Standards Track [Page 61] - -RFC 2060 IMAP4rev1 December 1996 - - - ENVELOPE A parenthesized list that describes the envelope - structure of a message. This is computed by the - server by parsing the [RFC-822] header into the - component parts, defaulting various fields as - necessary. - - The fields of the envelope structure are in the - following order: date, subject, from, sender, - reply-to, to, cc, bcc, in-reply-to, and message-id. - The date, subject, in-reply-to, and message-id - fields are strings. The from, sender, reply-to, - to, cc, and bcc fields are parenthesized lists of - address structures. - - An address structure is a parenthesized list that - describes an electronic mail address. The fields - of an address structure are in the following order: - personal name, [SMTP] at-domain-list (source - route), mailbox name, and host name. - - [RFC-822] group syntax is indicated by a special - form of address structure in which the host name - field is NIL. If the mailbox name field is also - NIL, this is an end of group marker (semi-colon in - RFC 822 syntax). If the mailbox name field is - non-NIL, this is a start of group marker, and the - mailbox name field holds the group name phrase. - - Any field of an envelope or address structure that - is not applicable is presented as NIL. Note that - the server MUST default the reply-to and sender - fields from the from field; a client is not - expected to know to do this. - - FLAGS A parenthesized list of flags that are set for this - message. - - INTERNALDATE A string representing the internal date of the - message. - - RFC822 Equivalent to BODY[]. - - RFC822.HEADER Equivalent to BODY.PEEK[HEADER]. - - RFC822.SIZE A number expressing the [RFC-822] size of the - message. - - RFC822.TEXT Equivalent to BODY[TEXT]. - - - -Crispin Standards Track [Page 62] - -RFC 2060 IMAP4rev1 December 1996 - - - UID A number expressing the unique identifier of the - message. - - - Example: S: * 23 FETCH (FLAGS (\Seen) RFC822.SIZE 44827) - -7.5. Server Responses - Command Continuation Request - - The command continuation request response is indicated by a "+" token - instead of a tag. This form of response indicates that the server is - ready to accept the continuation of a command from the client. The - remainder of this response is a line of text. - - This response is used in the AUTHORIZATION command to transmit server - data to the client, and request additional client data. This - response is also used if an argument to any command is a literal. - - The client is not permitted to send the octets of the literal unless - the server indicates that it expects it. This permits the server to - process commands and reject errors on a line-by-line basis. The - remainder of the command, including the CRLF that terminates a - command, follows the octets of the literal. If there are any - additional command arguments the literal octets are followed by a - space and those arguments. - - Example: C: A001 LOGIN {11} - S: + Ready for additional command text - C: FRED FOOBAR {7} - S: + Ready for additional command text - C: fat man - S: A001 OK LOGIN completed - C: A044 BLURDYBLOOP {102856} - S: A044 BAD No such command as "BLURDYBLOOP" - -8. Sample IMAP4rev1 connection - - The following is a transcript of an IMAP4rev1 connection. A long - line in this sample is broken for editorial clarity. - -S: * OK IMAP4rev1 Service Ready -C: a001 login mrc secret -S: a001 OK LOGIN completed -C: a002 select inbox -S: * 18 EXISTS -S: * FLAGS (\Answered \Flagged \Deleted \Seen \Draft) -S: * 2 RECENT -S: * OK [UNSEEN 17] Message 17 is the first unseen message -S: * OK [UIDVALIDITY 3857529045] UIDs valid - - - -Crispin Standards Track [Page 63] - -RFC 2060 IMAP4rev1 December 1996 - - -S: a002 OK [READ-WRITE] SELECT completed -C: a003 fetch 12 full -S: * 12 FETCH (FLAGS (\Seen) INTERNALDATE "17-Jul-1996 02:44:25 -0700" - RFC822.SIZE 4286 ENVELOPE ("Wed, 17 Jul 1996 02:23:25 -0700 (PDT)" - "IMAP4rev1 WG mtg summary and minutes" - (("Terry Gray" NIL "gray" "cac.washington.edu")) - (("Terry Gray" NIL "gray" "cac.washington.edu")) - (("Terry Gray" NIL "gray" "cac.washington.edu")) - ((NIL NIL "imap" "cac.washington.edu")) - ((NIL NIL "minutes" "CNRI.Reston.VA.US") - ("John Klensin" NIL "KLENSIN" "INFOODS.MIT.EDU")) NIL NIL - "<B27397-0100000@cac.washington.edu>") - BODY ("TEXT" "PLAIN" ("CHARSET" "US-ASCII") NIL NIL "7BIT" 3028 92)) -S: a003 OK FETCH completed -C: a004 fetch 12 body[header] -S: * 12 FETCH (BODY[HEADER] {350} -S: Date: Wed, 17 Jul 1996 02:23:25 -0700 (PDT) -S: From: Terry Gray <gray@cac.washington.edu> -S: Subject: IMAP4rev1 WG mtg summary and minutes -S: To: imap@cac.washington.edu -S: cc: minutes@CNRI.Reston.VA.US, John Klensin <KLENSIN@INFOODS.MIT.EDU> -S: Message-Id: <B27397-0100000@cac.washington.edu> -S: MIME-Version: 1.0 -S: Content-Type: TEXT/PLAIN; CHARSET=US-ASCII -S: -S: ) -S: a004 OK FETCH completed -C: a005 store 12 +flags \deleted -S: * 12 FETCH (FLAGS (\Seen \Deleted)) -S: a005 OK +FLAGS completed -C: a006 logout -S: * BYE IMAP4rev1 server terminating connection -S: a006 OK LOGOUT completed - -9. Formal Syntax - - The following syntax specification uses the augmented Backus-Naur - Form (BNF) notation as specified in [RFC-822] with one exception; the - delimiter used with the "#" construct is a single space (SPACE) and - not one or more commas. - - In the case of alternative or optional rules in which a later rule - overlaps an earlier rule, the rule which is listed earlier MUST take - priority. For example, "\Seen" when parsed as a flag is the \Seen - flag name and not a flag_extension, even though "\Seen" could be - parsed as a flag_extension. Some, but not all, instances of this - rule are noted below. - - - - -Crispin Standards Track [Page 64] - -RFC 2060 IMAP4rev1 December 1996 - - - Except as noted otherwise, all alphabetic characters are case- - insensitive. The use of upper or lower case characters to define - token strings is for editorial clarity only. Implementations MUST - accept these strings in a case-insensitive fashion. - -address ::= "(" addr_name SPACE addr_adl SPACE addr_mailbox - SPACE addr_host ")" - -addr_adl ::= nstring - ;; Holds route from [RFC-822] route-addr if - ;; non-NIL - -addr_host ::= nstring - ;; NIL indicates [RFC-822] group syntax. - ;; Otherwise, holds [RFC-822] domain name - -addr_mailbox ::= nstring - ;; NIL indicates end of [RFC-822] group; if - ;; non-NIL and addr_host is NIL, holds - ;; [RFC-822] group name. - ;; Otherwise, holds [RFC-822] local-part - -addr_name ::= nstring - ;; Holds phrase from [RFC-822] mailbox if - ;; non-NIL - -alpha ::= "A" / "B" / "C" / "D" / "E" / "F" / "G" / "H" / - "I" / "J" / "K" / "L" / "M" / "N" / "O" / "P" / - "Q" / "R" / "S" / "T" / "U" / "V" / "W" / "X" / - "Y" / "Z" / - "a" / "b" / "c" / "d" / "e" / "f" / "g" / "h" / - "i" / "j" / "k" / "l" / "m" / "n" / "o" / "p" / - "q" / "r" / "s" / "t" / "u" / "v" / "w" / "x" / - "y" / "z" - ;; Case-sensitive - -append ::= "APPEND" SPACE mailbox [SPACE flag_list] - [SPACE date_time] SPACE literal - -astring ::= atom / string - -atom ::= 1*ATOM_CHAR - -ATOM_CHAR ::= <any CHAR except atom_specials> - -atom_specials ::= "(" / ")" / "{" / SPACE / CTL / list_wildcards / - quoted_specials - - - - -Crispin Standards Track [Page 65] - -RFC 2060 IMAP4rev1 December 1996 - - -authenticate ::= "AUTHENTICATE" SPACE auth_type *(CRLF base64) - -auth_type ::= atom - ;; Defined by [IMAP-AUTH] - -base64 ::= *(4base64_char) [base64_terminal] - -base64_char ::= alpha / digit / "+" / "/" - -base64_terminal ::= (2base64_char "==") / (3base64_char "=") - -body ::= "(" body_type_1part / body_type_mpart ")" - -body_extension ::= nstring / number / "(" 1#body_extension ")" - ;; Future expansion. Client implementations - ;; MUST accept body_extension fields. Server - ;; implementations MUST NOT generate - ;; body_extension fields except as defined by - ;; future standard or standards-track - ;; revisions of this specification. - -body_ext_1part ::= body_fld_md5 [SPACE body_fld_dsp - [SPACE body_fld_lang - [SPACE 1#body_extension]]] - ;; MUST NOT be returned on non-extensible - ;; "BODY" fetch - -body_ext_mpart ::= body_fld_param - [SPACE body_fld_dsp SPACE body_fld_lang - [SPACE 1#body_extension]] - ;; MUST NOT be returned on non-extensible - ;; "BODY" fetch - -body_fields ::= body_fld_param SPACE body_fld_id SPACE - body_fld_desc SPACE body_fld_enc SPACE - body_fld_octets - -body_fld_desc ::= nstring - -body_fld_dsp ::= "(" string SPACE body_fld_param ")" / nil - -body_fld_enc ::= (<"> ("7BIT" / "8BIT" / "BINARY" / "BASE64"/ - "QUOTED-PRINTABLE") <">) / string - -body_fld_id ::= nstring - -body_fld_lang ::= nstring / "(" 1#string ")" - - - - -Crispin Standards Track [Page 66] - -RFC 2060 IMAP4rev1 December 1996 - - -body_fld_lines ::= number - -body_fld_md5 ::= nstring - -body_fld_octets ::= number - -body_fld_param ::= "(" 1#(string SPACE string) ")" / nil - -body_type_1part ::= (body_type_basic / body_type_msg / body_type_text) - [SPACE body_ext_1part] - -body_type_basic ::= media_basic SPACE body_fields - ;; MESSAGE subtype MUST NOT be "RFC822" - -body_type_mpart ::= 1*body SPACE media_subtype - [SPACE body_ext_mpart] - -body_type_msg ::= media_message SPACE body_fields SPACE envelope - SPACE body SPACE body_fld_lines - -body_type_text ::= media_text SPACE body_fields SPACE body_fld_lines - -capability ::= "AUTH=" auth_type / atom - ;; New capabilities MUST begin with "X" or be - ;; registered with IANA as standard or - ;; standards-track - -capability_data ::= "CAPABILITY" SPACE [1#capability SPACE] "IMAP4rev1" - [SPACE 1#capability] - ;; IMAP4rev1 servers which offer RFC 1730 - ;; compatibility MUST list "IMAP4" as the first - ;; capability. - -CHAR ::= <any 7-bit US-ASCII character except NUL, - 0x01 - 0x7f> - -CHAR8 ::= <any 8-bit octet except NUL, 0x01 - 0xff> - -command ::= tag SPACE (command_any / command_auth / - command_nonauth / command_select) CRLF - ;; Modal based on state - -command_any ::= "CAPABILITY" / "LOGOUT" / "NOOP" / x_command - ;; Valid in all states - -command_auth ::= append / create / delete / examine / list / lsub / - rename / select / status / subscribe / unsubscribe - ;; Valid only in Authenticated or Selected state - - - -Crispin Standards Track [Page 67] - -RFC 2060 IMAP4rev1 December 1996 - - -command_nonauth ::= login / authenticate - ;; Valid only when in Non-Authenticated state - -command_select ::= "CHECK" / "CLOSE" / "EXPUNGE" / - copy / fetch / store / uid / search - ;; Valid only when in Selected state - -continue_req ::= "+" SPACE (resp_text / base64) - -copy ::= "COPY" SPACE set SPACE mailbox - -CR ::= <ASCII CR, carriage return, 0x0D> - -create ::= "CREATE" SPACE mailbox - ;; Use of INBOX gives a NO error - -CRLF ::= CR LF - -CTL ::= <any ASCII control character and DEL, - 0x00 - 0x1f, 0x7f> - -date ::= date_text / <"> date_text <"> - -date_day ::= 1*2digit - ;; Day of month - -date_day_fixed ::= (SPACE digit) / 2digit - ;; Fixed-format version of date_day - -date_month ::= "Jan" / "Feb" / "Mar" / "Apr" / "May" / "Jun" / - "Jul" / "Aug" / "Sep" / "Oct" / "Nov" / "Dec" - -date_text ::= date_day "-" date_month "-" date_year - -date_year ::= 4digit - -date_time ::= <"> date_day_fixed "-" date_month "-" date_year - SPACE time SPACE zone <"> - -delete ::= "DELETE" SPACE mailbox - ;; Use of INBOX gives a NO error - -digit ::= "0" / digit_nz - -digit_nz ::= "1" / "2" / "3" / "4" / "5" / "6" / "7" / "8" / - "9" - - - - - -Crispin Standards Track [Page 68] - -RFC 2060 IMAP4rev1 December 1996 - - -envelope ::= "(" env_date SPACE env_subject SPACE env_from - SPACE env_sender SPACE env_reply_to SPACE env_to - SPACE env_cc SPACE env_bcc SPACE env_in_reply_to - SPACE env_message_id ")" - -env_bcc ::= "(" 1*address ")" / nil - -env_cc ::= "(" 1*address ")" / nil - -env_date ::= nstring - -env_from ::= "(" 1*address ")" / nil - -env_in_reply_to ::= nstring - -env_message_id ::= nstring - -env_reply_to ::= "(" 1*address ")" / nil - -env_sender ::= "(" 1*address ")" / nil - -env_subject ::= nstring - -env_to ::= "(" 1*address ")" / nil - -examine ::= "EXAMINE" SPACE mailbox - -fetch ::= "FETCH" SPACE set SPACE ("ALL" / "FULL" / - "FAST" / fetch_att / "(" 1#fetch_att ")") - -fetch_att ::= "ENVELOPE" / "FLAGS" / "INTERNALDATE" / - "RFC822" [".HEADER" / ".SIZE" / ".TEXT"] / - "BODY" ["STRUCTURE"] / "UID" / - "BODY" [".PEEK"] section - ["<" number "." nz_number ">"] - -flag ::= "\Answered" / "\Flagged" / "\Deleted" / - "\Seen" / "\Draft" / flag_keyword / flag_extension - -flag_extension ::= "\" atom - ;; Future expansion. Client implementations - ;; MUST accept flag_extension flags. Server - ;; implementations MUST NOT generate - ;; flag_extension flags except as defined by - ;; future standard or standards-track - ;; revisions of this specification. - -flag_keyword ::= atom - - - -Crispin Standards Track [Page 69] - -RFC 2060 IMAP4rev1 December 1996 - - -flag_list ::= "(" #flag ")" - -greeting ::= "*" SPACE (resp_cond_auth / resp_cond_bye) CRLF - -header_fld_name ::= astring - -header_list ::= "(" 1#header_fld_name ")" - -LF ::= <ASCII LF, line feed, 0x0A> - -list ::= "LIST" SPACE mailbox SPACE list_mailbox - -list_mailbox ::= 1*(ATOM_CHAR / list_wildcards) / string - -list_wildcards ::= "%" / "*" - -literal ::= "{" number "}" CRLF *CHAR8 - ;; Number represents the number of CHAR8 octets - -login ::= "LOGIN" SPACE userid SPACE password - -lsub ::= "LSUB" SPACE mailbox SPACE list_mailbox - -mailbox ::= "INBOX" / astring - ;; INBOX is case-insensitive. All case variants of - ;; INBOX (e.g. "iNbOx") MUST be interpreted as INBOX - ;; not as an astring. Refer to section 5.1 for - ;; further semantic details of mailbox names. - -mailbox_data ::= "FLAGS" SPACE flag_list / - "LIST" SPACE mailbox_list / - "LSUB" SPACE mailbox_list / - "MAILBOX" SPACE text / - "SEARCH" [SPACE 1#nz_number] / - "STATUS" SPACE mailbox SPACE - "(" #<status_att number ")" / - number SPACE "EXISTS" / number SPACE "RECENT" - -mailbox_list ::= "(" #("\Marked" / "\Noinferiors" / - "\Noselect" / "\Unmarked" / flag_extension) ")" - SPACE (<"> QUOTED_CHAR <"> / nil) SPACE mailbox - -media_basic ::= (<"> ("APPLICATION" / "AUDIO" / "IMAGE" / - "MESSAGE" / "VIDEO") <">) / string) - SPACE media_subtype - ;; Defined in [MIME-IMT] - -media_message ::= <"> "MESSAGE" <"> SPACE <"> "RFC822" <"> - - - -Crispin Standards Track [Page 70] - -RFC 2060 IMAP4rev1 December 1996 - - - ;; Defined in [MIME-IMT] - -media_subtype ::= string - ;; Defined in [MIME-IMT] - -media_text ::= <"> "TEXT" <"> SPACE media_subtype - ;; Defined in [MIME-IMT] - -message_data ::= nz_number SPACE ("EXPUNGE" / - ("FETCH" SPACE msg_att)) - -msg_att ::= "(" 1#("ENVELOPE" SPACE envelope / - "FLAGS" SPACE "(" #(flag / "\Recent") ")" / - "INTERNALDATE" SPACE date_time / - "RFC822" [".HEADER" / ".TEXT"] SPACE nstring / - "RFC822.SIZE" SPACE number / - "BODY" ["STRUCTURE"] SPACE body / - "BODY" section ["<" number ">"] SPACE nstring / - "UID" SPACE uniqueid) ")" - -nil ::= "NIL" - -nstring ::= string / nil - -number ::= 1*digit - ;; Unsigned 32-bit integer - ;; (0 <= n < 4,294,967,296) - -nz_number ::= digit_nz *digit - ;; Non-zero unsigned 32-bit integer - ;; (0 < n < 4,294,967,296) - -password ::= astring - -quoted ::= <"> *QUOTED_CHAR <"> - -QUOTED_CHAR ::= <any TEXT_CHAR except quoted_specials> / - "\" quoted_specials - -quoted_specials ::= <"> / "\" - -rename ::= "RENAME" SPACE mailbox SPACE mailbox - ;; Use of INBOX as a destination gives a NO error - -response ::= *(continue_req / response_data) response_done - -response_data ::= "*" SPACE (resp_cond_state / resp_cond_bye / - mailbox_data / message_data / capability_data) - - - -Crispin Standards Track [Page 71] - -RFC 2060 IMAP4rev1 December 1996 - - - CRLF - -response_done ::= response_tagged / response_fatal - -response_fatal ::= "*" SPACE resp_cond_bye CRLF - ;; Server closes connection immediately - -response_tagged ::= tag SPACE resp_cond_state CRLF - -resp_cond_auth ::= ("OK" / "PREAUTH") SPACE resp_text - ;; Authentication condition - -resp_cond_bye ::= "BYE" SPACE resp_text - -resp_cond_state ::= ("OK" / "NO" / "BAD") SPACE resp_text - ;; Status condition - -resp_text ::= ["[" resp_text_code "]" SPACE] (text_mime2 / text) - ;; text SHOULD NOT begin with "[" or "=" - -resp_text_code ::= "ALERT" / "PARSE" / - "PERMANENTFLAGS" SPACE "(" #(flag / "\*") ")" / - "READ-ONLY" / "READ-WRITE" / "TRYCREATE" / - "UIDVALIDITY" SPACE nz_number / - "UNSEEN" SPACE nz_number / - atom [SPACE 1*<any TEXT_CHAR except "]">] - -search ::= "SEARCH" SPACE ["CHARSET" SPACE astring SPACE] - 1#search_key - ;; [CHARSET] MUST be registered with IANA - -search_key ::= "ALL" / "ANSWERED" / "BCC" SPACE astring / - "BEFORE" SPACE date / "BODY" SPACE astring / - "CC" SPACE astring / "DELETED" / "FLAGGED" / - "FROM" SPACE astring / - "KEYWORD" SPACE flag_keyword / "NEW" / "OLD" / - "ON" SPACE date / "RECENT" / "SEEN" / - "SINCE" SPACE date / "SUBJECT" SPACE astring / - "TEXT" SPACE astring / "TO" SPACE astring / - "UNANSWERED" / "UNDELETED" / "UNFLAGGED" / - "UNKEYWORD" SPACE flag_keyword / "UNSEEN" / - ;; Above this line were in [IMAP2] - "DRAFT" / - "HEADER" SPACE header_fld_name SPACE astring / - "LARGER" SPACE number / "NOT" SPACE search_key / - "OR" SPACE search_key SPACE search_key / - "SENTBEFORE" SPACE date / "SENTON" SPACE date / - "SENTSINCE" SPACE date / "SMALLER" SPACE number / - - - -Crispin Standards Track [Page 72] - -RFC 2060 IMAP4rev1 December 1996 - - - "UID" SPACE set / "UNDRAFT" / set / - "(" 1#search_key ")" - -section ::= "[" [section_text / (nz_number *["." nz_number] - ["." (section_text / "MIME")])] "]" - -section_text ::= "HEADER" / "HEADER.FIELDS" [".NOT"] - SPACE header_list / "TEXT" - -select ::= "SELECT" SPACE mailbox - -sequence_num ::= nz_number / "*" - ;; * is the largest number in use. For message - ;; sequence numbers, it is the number of messages - ;; in the mailbox. For unique identifiers, it is - ;; the unique identifier of the last message in - ;; the mailbox. - -set ::= sequence_num / (sequence_num ":" sequence_num) / - (set "," set) - ;; Identifies a set of messages. For message - ;; sequence numbers, these are consecutive - ;; numbers from 1 to the number of messages in - ;; the mailbox - ;; Comma delimits individual numbers, colon - ;; delimits between two numbers inclusive. - ;; Example: 2,4:7,9,12:* is 2,4,5,6,7,9,12,13, - ;; 14,15 for a mailbox with 15 messages. - -SPACE ::= <ASCII SP, space, 0x20> - -status ::= "STATUS" SPACE mailbox SPACE "(" 1#status_att ")" - -status_att ::= "MESSAGES" / "RECENT" / "UIDNEXT" / "UIDVALIDITY" / - "UNSEEN" - -store ::= "STORE" SPACE set SPACE store_att_flags - -store_att_flags ::= (["+" / "-"] "FLAGS" [".SILENT"]) SPACE - (flag_list / #flag) - -string ::= quoted / literal - -subscribe ::= "SUBSCRIBE" SPACE mailbox - -tag ::= 1*<any ATOM_CHAR except "+"> - -text ::= 1*TEXT_CHAR - - - -Crispin Standards Track [Page 73] - -RFC 2060 IMAP4rev1 December 1996 - - -text_mime2 ::= "=?" <charset> "?" <encoding> "?" - <encoded-text> "?=" - ;; Syntax defined in [MIME-HDRS] - -TEXT_CHAR ::= <any CHAR except CR and LF> - -time ::= 2digit ":" 2digit ":" 2digit - ;; Hours minutes seconds - -uid ::= "UID" SPACE (copy / fetch / search / store) - ;; Unique identifiers used instead of message - ;; sequence numbers - -uniqueid ::= nz_number - ;; Strictly ascending - -unsubscribe ::= "UNSUBSCRIBE" SPACE mailbox - -userid ::= astring - -x_command ::= "X" atom <experimental command arguments> - -zone ::= ("+" / "-") 4digit - ;; Signed four-digit value of hhmm representing - ;; hours and minutes west of Greenwich (that is, - ;; (the amount that the given time differs from - ;; Universal Time). Subtracting the timezone - ;; from the given time will give the UT form. - ;; The Universal Time zone is "+0000". - -10. Author's Note - - This document is a revision or rewrite of earlier documents, and - supercedes the protocol specification in those documents: RFC 1730, - unpublished IMAP2bis.TXT document, RFC 1176, and RFC 1064. - -11. Security Considerations - - IMAP4rev1 protocol transactions, including electronic mail data, are - sent in the clear over the network unless privacy protection is - negotiated in the AUTHENTICATE command. - - A server error message for an AUTHENTICATE command which fails due to - invalid credentials SHOULD NOT detail why the credentials are - invalid. - - Use of the LOGIN command sends passwords in the clear. This can be - avoided by using the AUTHENTICATE command instead. - - - -Crispin Standards Track [Page 74] - -RFC 2060 IMAP4rev1 December 1996 - - - A server error message for a failing LOGIN command SHOULD NOT specify - that the user name, as opposed to the password, is invalid. - - Additional security considerations are discussed in the section - discussing the AUTHENTICATE and LOGIN commands. - -12. Author's Address - - Mark R. Crispin - Networks and Distributed Computing - University of Washington - 4545 15th Aveneue NE - Seattle, WA 98105-4527 - - Phone: (206) 543-5762 - - EMail: MRC@CAC.Washington.EDU - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Crispin Standards Track [Page 75] - -RFC 2060 IMAP4rev1 December 1996 - - -Appendices - -A. References - -[ACAP] Myers, J. "ACAP -- Application Configuration Access Protocol", -Work in Progress. - -[CHARSET] Reynolds, J., and J. Postel, "Assigned Numbers", STD 2, -RFC 1700, USC/Information Sciences Institute, October 1994. - -[DISPOSITION] Troost, R., and Dorner, S., "Communicating Presentation -Information in Internet Messages: The Content-Disposition Header", -RFC 1806, June 1995. - -[IMAP-AUTH] Myers, J., "IMAP4 Authentication Mechanism", RFC 1731. -Carnegie-Mellon University, December 1994. - -[IMAP-COMPAT] Crispin, M., "IMAP4 Compatibility with IMAP2bis", RFC -2061, University of Washington, November 1996. - -[IMAP-DISC] Austein, R., "Synchronization Operations for Disconnected -IMAP4 Clients", Work in Progress. - -[IMAP-HISTORICAL] Crispin, M. "IMAP4 Compatibility with IMAP2 and -IMAP2bis", RFC 1732, University of Washington, December 1994. - -[IMAP-MODEL] Crispin, M., "Distributed Electronic Mail Models in -IMAP4", RFC 1733, University of Washington, December 1994. - -[IMAP-OBSOLETE] Crispin, M., "Internet Message Access Protocol - -Obsolete Syntax", RFC 2062, University of Washington, November 1996. - -[IMAP2] Crispin, M., "Interactive Mail Access Protocol - Version 2", -RFC 1176, University of Washington, August 1990. - -[LANGUAGE-TAGS] Alvestrand, H., "Tags for the Identification of -Languages", RFC 1766, March 1995. - -[MD5] Myers, J., and M. Rose, "The Content-MD5 Header Field", RFC -1864, October 1995. - -[MIME-IMB] Freed, N., and N. Borenstein, "MIME (Multipurpose Internet -Mail Extensions) Part One: Format of Internet Message Bodies", RFC -2045, November 1996. - -[MIME-IMT] Freed, N., and N. Borenstein, "MIME (Multipurpose -Internet Mail Extensions) Part Two: Media Types", RFC 2046, -November 1996. - - - -Crispin Standards Track [Page 76] - -RFC 2060 IMAP4rev1 December 1996 - - -[MIME-HDRS] Moore, K., "MIME (Multipurpose Internet Mail Extensions) -Part Three: Message Header Extensions for Non-ASCII Text", RFC -2047, November 1996. - -[RFC-822] Crocker, D., "Standard for the Format of ARPA Internet Text -Messages", STD 11, RFC 822, University of Delaware, August 1982. - -[SMTP] Postel, J., "Simple Mail Transfer Protocol", STD 10, -RFC 821, USC/Information Sciences Institute, August 1982. - -[UTF-7] Goldsmith, D., and Davis, M., "UTF-7: A Mail-Safe -Transformation Format of Unicode", RFC 1642, July 1994. - -B. Changes from RFC 1730 - -1) The STATUS command has been added. - -2) Clarify in the formal syntax that the "#" construct can never -refer to multiple spaces. - -3) Obsolete syntax has been moved to a separate document. - -4) The PARTIAL command has been obsoleted. - -5) The RFC822.HEADER.LINES, RFC822.HEADER.LINES.NOT, RFC822.PEEK, and -RFC822.TEXT.PEEK fetch attributes have been obsoleted. - -6) The "<" origin "." size ">" suffix for BODY text attributes has -been added. - -7) The HEADER, HEADER.FIELDS, HEADER.FIELDS.NOT, MIME, and TEXT part -specifiers have been added. - -8) Support for Content-Disposition and Content-Language has been -added. - -9) The restriction on fetching nested MULTIPART parts has been -removed. - -10) Body part number 0 has been obsoleted. - -11) Server-supported authenticators are now identified by -capabilities. - - - - - - - - -Crispin Standards Track [Page 77] - -RFC 2060 IMAP4rev1 December 1996 - - -12) The capability that identifies this protocol is now called -"IMAP4rev1". A server that provides backwards support for RFC 1730 -SHOULD emit the "IMAP4" capability in addition to "IMAP4rev1" in its -CAPABILITY response. Because RFC-1730 required "IMAP4" to appear as -the first capability, it MUST listed first in the response. - -13) A description of the mailbox name namespace convention has been -added. - -14) A description of the international mailbox name convention has -been added. - -15) The UID-NEXT and UID-VALIDITY status items are now called UIDNEXT -and UIDVALIDITY. This is a change from the IMAP STATUS -Work in Progress and not from RFC-1730 - -16) Add a clarification that a null mailbox name argument to the LIST -command returns an untagged LIST response with the hierarchy -delimiter and root of the reference argument. - -17) Define terms such as "MUST", "SHOULD", and "MUST NOT". - -18) Add a section which defines message attributes and more -thoroughly details the semantics of message sequence numbers, UIDs, -and flags. - -19) Add a clarification detailing the circumstances when a client may -send multiple commands without waiting for a response, and the -circumstances in which ambiguities may result. - -20) Add a recommendation on server behavior for DELETE and RENAME -when inferior hierarchical names of the given name exist. - -21) Add a clarification that a mailbox name may not be unilaterally -unsubscribed by the server, even if that mailbox name no longer -exists. - -22) Add a clarification that LIST should return its results quickly -without undue delay. - -23) Add a clarification that the date_time argument to APPEND sets -the internal date of the message. - -24) Add a clarification on APPEND behavior when the target mailbox is -the currently selected mailbox. - - - - - - -Crispin Standards Track [Page 78] - -RFC 2060 IMAP4rev1 December 1996 - - -25) Add a clarification that external changes to flags should be -always announced via an untagged FETCH even if the current command is -a STORE with the ".SILENT" suffix. - -26) Add a clarification that COPY appends to the target mailbox. - -27) Add the NEWNAME response code. - -28) Rewrite the description of the untagged BYE response to clarify -its semantics. - -29) Change the reference for the body MD5 to refer to the proper RFC. - -30) Clarify that the formal syntax contains rules which may overlap, -and that in the event of such an overlap the rule which occurs first -takes precedence. - -31) Correct the definition of body_fld_param. - -32) More formal syntax for capability_data. - -33) Clarify that any case variant of "INBOX" must be interpreted as -INBOX. - -34) Clarify that the human-readable text in resp_text should not -begin with "[" or "=". - -35) Change MIME references to Draft Standard documents. - -36) Clarify \Recent semantics. - -37) Additional examples. - -C. Key Word Index - - +FLAGS <flag list> (store command data item) ............... 45 - +FLAGS.SILENT <flag list> (store command data item) ........ 46 - -FLAGS <flag list> (store command data item) ............... 46 - -FLAGS.SILENT <flag list> (store command data item) ........ 46 - ALERT (response code) ...................................... 50 - ALL (fetch item) ........................................... 41 - ALL (search key) ........................................... 38 - ANSWERED (search key) ...................................... 38 - APPEND (command) ........................................... 34 - AUTHENTICATE (command) ..................................... 20 - BAD (response) ............................................. 52 - BCC <string> (search key) .................................. 38 - BEFORE <date> (search key) ................................. 39 - - - -Crispin Standards Track [Page 79] - -RFC 2060 IMAP4rev1 December 1996 - - - BODY (fetch item) .......................................... 41 - BODY (fetch result) ........................................ 58 - BODY <string> (search key) ................................. 39 - BODY.PEEK[<section>]<<partial>> (fetch item) ............... 44 - BODYSTRUCTURE (fetch item) ................................. 44 - BODYSTRUCTURE (fetch result) ............................... 59 - BODY[<section>]<<origin_octet>> (fetch result) ............. 58 - BODY[<section>]<<partial>> (fetch item) .................... 41 - BYE (response) ............................................. 52 - Body Structure (message attribute) ......................... 11 - CAPABILITY (command) ....................................... 18 - CAPABILITY (response) ...................................... 53 - CC <string> (search key) ................................... 39 - CHECK (command) ............................................ 36 - CLOSE (command) ............................................ 36 - COPY (command) ............................................. 46 - CREATE (command) ........................................... 25 - DELETE (command) ........................................... 26 - DELETED (search key) ....................................... 39 - DRAFT (search key) ......................................... 39 - ENVELOPE (fetch item) ...................................... 44 - ENVELOPE (fetch result) .................................... 62 - EXAMINE (command) .......................................... 24 - EXISTS (response) .......................................... 56 - EXPUNGE (command) .......................................... 37 - EXPUNGE (response) ......................................... 57 - Envelope Structure (message attribute) ..................... 11 - FAST (fetch item) .......................................... 44 - FETCH (command) ............................................ 41 - FETCH (response) ........................................... 58 - FLAGGED (search key) ....................................... 39 - FLAGS (fetch item) ......................................... 44 - FLAGS (fetch result) ....................................... 62 - FLAGS (response) ........................................... 56 - FLAGS <flag list> (store command data item) ................ 45 - FLAGS.SILENT <flag list> (store command data item) ......... 45 - FROM <string> (search key) ................................. 39 - FULL (fetch item) .......................................... 44 - Flags (message attribute) .................................. 9 - HEADER (part specifier) .................................... 41 - HEADER <field-name> <string> (search key) .................. 39 - HEADER.FIELDS <header_list> (part specifier) ............... 41 - HEADER.FIELDS.NOT <header_list> (part specifier) ........... 41 - INTERNALDATE (fetch item) .................................. 44 - INTERNALDATE (fetch result) ................................ 62 - Internal Date (message attribute) .......................... 10 - KEYWORD <flag> (search key) ................................ 39 - Keyword (type of flag) ..................................... 10 - - - -Crispin Standards Track [Page 80] - -RFC 2060 IMAP4rev1 December 1996 - - - LARGER <n> (search key) .................................... 39 - LIST (command) ............................................. 30 - LIST (response) ............................................ 54 - LOGIN (command) ............................................ 22 - LOGOUT (command) ........................................... 20 - LSUB (command) ............................................. 32 - LSUB (response) ............................................ 55 - MAY (specification requirement term) ....................... 5 - MESSAGES (status item) ..................................... 33 - MIME (part specifier) ...................................... 42 - MUST (specification requirement term) ...................... 4 - MUST NOT (specification requirement term) .................. 4 - Message Sequence Number (message attribute) ................ 9 - NEW (search key) ........................................... 39 - NEWNAME (response code) .................................... 50 - NO (response) .............................................. 51 - NOOP (command) ............................................. 19 - NOT <search-key> (search key) .............................. 39 - OK (response) .............................................. 51 - OLD (search key) ........................................... 39 - ON <date> (search key) ..................................... 39 - OPTIONAL (specification requirement term) .................. 5 - OR <search-key1> <search-key2> (search key) ................ 39 - PARSE (response code) ...................................... 50 - PERMANENTFLAGS (response code) ............................. 50 - PREAUTH (response) ......................................... 52 - Permanent Flag (class of flag) ............................. 10 - READ-ONLY (response code) .................................. 50 - READ-WRITE (response code) ................................. 50 - RECENT (response) .......................................... 57 - RECENT (search key) ........................................ 39 - RECENT (status item) ....................................... 33 - RENAME (command) ........................................... 27 - REQUIRED (specification requirement term) .................. 4 - RFC822 (fetch item) ........................................ 44 - RFC822 (fetch result) ...................................... 63 - RFC822.HEADER (fetch item) ................................. 44 - RFC822.HEADER (fetch result) ............................... 62 - RFC822.SIZE (fetch item) ................................... 44 - RFC822.SIZE (fetch result) ................................. 62 - RFC822.TEXT (fetch item) ................................... 44 - RFC822.TEXT (fetch result) ................................. 62 - SEARCH (command) ........................................... 37 - SEARCH (response) .......................................... 55 - SEEN (search key) .......................................... 40 - SELECT (command) ........................................... 23 - SENTBEFORE <date> (search key) ............................. 40 - SENTON <date> (search key) ................................. 40 - - - -Crispin Standards Track [Page 81] - -RFC 2060 IMAP4rev1 December 1996 - - - SENTSINCE <date> (search key) .............................. 40 - SHOULD (specification requirement term) .................... 5 - SHOULD NOT (specification requirement term) ................ 5 - SINCE <date> (search key) .................................. 40 - SMALLER <n> (search key) ................................... 40 - STATUS (command) ........................................... 33 - STATUS (response) .......................................... 55 - STORE (command) ............................................ 45 - SUBJECT <string> (search key) .............................. 40 - SUBSCRIBE (command) ........................................ 29 - Session Flag (class of flag) ............................... 10 - System Flag (type of flag) ................................. 9 - TEXT (part specifier) ...................................... 42 - TEXT <string> (search key) ................................. 40 - TO <string> (search key) ................................... 40 - TRYCREATE (response code) .................................. 51 - UID (command) .............................................. 47 - UID (fetch item) ........................................... 44 - UID (fetch result) ......................................... 63 - UID <message set> (search key) ............................. 40 - UIDNEXT (status item) ...................................... 33 - UIDVALIDITY (response code) ................................ 51 - UIDVALIDITY (status item) .................................. 34 - UNANSWERED (search key) .................................... 40 - UNDELETED (search key) ..................................... 40 - UNDRAFT (search key) ....................................... 40 - UNFLAGGED (search key) ..................................... 40 - UNKEYWORD <flag> (search key) .............................. 40 - UNSEEN (response code) ..................................... 51 - UNSEEN (search key) ........................................ 40 - UNSEEN (status item) ....................................... 34 - UNSUBSCRIBE (command) ...................................... 30 - Unique Identifier (UID) (message attribute) ................ 7 - X<atom> (command) .......................................... 48 - [RFC-822] Size (message attribute) ......................... 11 - \Answered (system flag) .................................... 9 - \Deleted (system flag) ..................................... 9 - \Draft (system flag) ....................................... 9 - \Flagged (system flag) ..................................... 9 - \Marked (mailbox name attribute) ........................... 54 - \Noinferiors (mailbox name attribute) ...................... 54 - \Noselect (mailbox name attribute) ......................... 54 - \Recent (system flag) ...................................... 10 - \Seen (system flag) ........................................ 9 - \Unmarked (mailbox name attribute) ......................... 54 - - - - - - -Crispin Standards Track [Page 82] - |