diff options
author | Eric S. Raymond <esr@thyrsus.com> | 2000-03-06 20:24:47 +0000 |
---|---|---|
committer | Eric S. Raymond <esr@thyrsus.com> | 2000-03-06 20:24:47 +0000 |
commit | b207b3e0065226b86c13ccb636cd91db34c24da2 (patch) | |
tree | 0c3fd6a7e8d376c01ea0a851eafd57c3e801386f /fetchmail-FAQ.html | |
parent | 582012e400e28648a602804eeea6d701f2295306 (diff) | |
download | fetchmail-b207b3e0065226b86c13ccb636cd91db34c24da2.tar.gz fetchmail-b207b3e0065226b86c13ccb636cd91db34c24da2.tar.bz2 fetchmail-b207b3e0065226b86c13ccb636cd91db34c24da2.zip |
Added FAQ item X6.
svn path=/trunk/; revision=2800
Diffstat (limited to 'fetchmail-FAQ.html')
-rw-r--r-- | fetchmail-FAQ.html | 101 |
1 files changed, 96 insertions, 5 deletions
diff --git a/fetchmail-FAQ.html b/fetchmail-FAQ.html index 271b1aa6..4ff55724 100644 --- a/fetchmail-FAQ.html +++ b/fetchmail-FAQ.html @@ -10,7 +10,7 @@ <table width="100%" cellpadding=0><tr> <td width="30%">Back to <a href="index.html">Fetchmail Home Page</a> <td width="30%" align=center>To <a href="/~esr/sitemap.html">Site Map</a> -<td width="30%" align=right>$Date: 2000/03/06 07:19:35 $ +<td width="30%" align=right>$Date: 2000/03/06 20:24:47 $ </table> <HR> <H1>Frequently Asked Questions About Fetchmail</H1> @@ -136,6 +136,7 @@ my Received headers as it should.</a><br> <a href="#X3">X3. Messages containing "From" at start of line are being split.</a><br> <a href="#X4">X4. My mail is being mangled in a new and different way.</a><br> <a href="#X5">X5. Using POP3, retrievals seems to be fetching too much!</a><br> +<a href="#X6">X6. My mail attachments are being dropped or mangled.</a><br> <h1>Other problems:</h1> @@ -2497,9 +2498,99 @@ TOP argument in 4.4.7 fixed this.<P> Fix: Upgrade to a later version of fetchmail.<P> -Workaround: set the <code>fetchall</code> option. Under POP3 in these -fetchmail version only, this had the side effect of forcing RETR -use.<P> +Workaround: set the <code>fetchall</code> option. Under POP3 +this has the side effect of forcing RETR use.<P> + +<hr> +<h2><a name="X6">X6. My mail attachments are being dropped or mangled.</a></h2> + +This isn't fetchmail's doing -- fetchmail never drops lines in message +bodies or attachments. It may be your POP server, or it may be the +sender's mail user agent (or a bad combination of both).<p> + +The Mail Max POP3 server and the InterChange and Imail IMAP servers +are known to simply drop MIME attachments when uploading messages. +We've had sporadic reports of problems with Microsoft Exchange and +Outlook servers. Windows- and NT-based POP servers seem especially +prone to mangle attachments. If you are running one of these, +replacing your server with a Unix machine is probably the only +effective solution.<p> + +Rob Funk explains: Unfortunately there also remain many mail user +agents that don't write correct MIME messages. One big offender is Sun +MailTool attachments, which are formatted enough like MIME that some +programs could get confused; these are generated by the mailtool and +dtmail programs (the mail programs in Sun's OpenWindows and CDE +environments).<p> + +One solution to problems related to misformatted MIME attachments is +the <a href="ftp://ftp.uu.se/pub/unix/networking/mail/emil/">emil</a> +program; see its <a +href="ftp://ftp.uu.se/pub/unix/networking/mail/emil/TUTORIAL.html">tutorial</a> +file at that site for details on emil. It is useful for +converting character sets, attachment encodings, and attachment +formats. At this writing, emil does not appear to have been +maintained since a patch to version 2.1.0beta9 in late 1997, but it is +still useful.<p> + +One good way of using emil is from within procmail. You can have +procmail look for signs of problematic message formatting, and pipe +those messages through emil to be fixed. emil will not always be able +to fix the problem, in which case the message is unchanged.<p> + +A possible rule to be inserted into a .procmailrc file for using emil +would be: + +<pre> +:0HB +* 1^1 ^Content-Type: \/X-sun[^;]* +* 1^1 ^Content-Type: \/application/mac-binhex[^;]* +* 1^1 ^Content-Transfer-Encoding: \/x-binhex[^;]* +* 1^1 ^Content-Transfer-Encoding: \/x-uuencode[^;]* +{ + LOG="Converting $MATCH +" + :0fw + | emil -A B -T Q -B BA -C iso-8859-1 -H Q -F MIME | gawk ++'{gsub(/\r\n?/,"\n");print $0}' +} +</pre> + +The "1^1" in the conditions is a way of specifying to procmail that if +any one of the four listed expressions is found in the message, the +total condition is considered true, and the message gets passed into +emil. These four subconditions check whether the message has a Sun +attachment, a binhex attachment, or a uuencoded attachment; there are +others that could be added to check these things better and to check +other relevant conditions. The "LOG=" line writes a line into the +procmail log; the lone double-quote beginning the following line makes +sure the log entry gets an end-of-line character. The call to gawk +(GNU awk) is for fixing end-of-line conventions, since emil sometimes +leaves those in the format of the originating machine; it could +probably be replaced with a sed subsitution.<p> + +The emil call itself tries to ensure that the message uses: +<ul> +<li> BinHex encoding for any Apple Macintosh-only attachments +<li> Quoted-Printable encoding for text (when necessary) +<li> Base64 Encoding for binary attachments +<li> iso-8859-1 character set for text (unfortunately emil can't yet + convert from windows-1252 to iso-8859-1) +<li> Quoted-Printable encoding for headers +<li> MIME attachment format +</ul> + +Most of these (the primary exceptions being the character set and the +Apple binary format) are as they should be for good internet +interoperability.<p> + +Some mail servers (Lotus Domino is a suspect here) mangle +Sun-formatted messages, so the conversion to MIME needs to happen +before such programs see the message. The ideal is to rid the world +of Sun-formatted messages: don't use mailtool for sending attachments +(it doesn't understand MIME anyway, and most of the world doesn't +understand its attachments, so it really shouldn't be used at all), +and make sure dtmail is set to use MIME rather than mailtool's format.<p> <hr> <h2><a name="O1">O1. The --logfile option doesn't work if the logfile doesn't exist.</a></h2> @@ -2668,7 +2759,7 @@ terminate it.<p> <table width="100%" cellpadding=0><tr> <td width="30%">Back to <a href="index.html">Fetchmail Home Page</a> <td width="30%" align=center>To <a href="/~esr/sitemap.html">Site Map</a> -<td width="30%" align=right>$Date: 2000/03/06 07:19:35 $ +<td width="30%" align=right>$Date: 2000/03/06 20:24:47 $ </table> <P><ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> |