From ac58d06e7a275cd8cb33758d5b23a5226c469c63 Mon Sep 17 00:00:00 2001 From: "Eric S. Raymond" Date: Fri, 31 Jul 1998 20:56:28 +0000 Subject: Updated FAQ. svn path=/trunk/; revision=2031 --- fetchmail-FAQ.html | 89 ++++++++++++++++++++---------------------------------- 1 file changed, 32 insertions(+), 57 deletions(-) (limited to 'fetchmail-FAQ.html') diff --git a/fetchmail-FAQ.html b/fetchmail-FAQ.html index b5535085..3c8340f5 100644 --- a/fetchmail-FAQ.html +++ b/fetchmail-FAQ.html @@ -10,7 +10,7 @@
Back to Fetchmail Home Page To Site Map -$Date: 1998/07/25 18:15:58 $ +$Date: 1998/07/31 20:56:28 $

Frequently Asked Questions About Fetchmail

@@ -55,7 +55,7 @@ IP address?
C1. Why do I need a .fetchmailrc when running as root on my own machine?
C2. How can I arrange for a fetchmail daemon to get killed when I log out?
C3. How do I know what interface and address to use with --interface?
-C4. How can I set up support for sendmail's anti-spam 571 response?
+C4. How can I set up support for sendmail's anti-spam features?

How to make fetchmail play nice with other software:

@@ -831,73 +831,48 @@ would work. To range over any value of the last two octets
-

C4. How can I set up support for sendmail's anti-spam 571 response?

+

C4. How can I set up support for sendmail's anti-spam features?

-Rachel Polanskis writes:

+This answer covers versions of sendmail from 8.8.7 (the version +installed in Red Hat 5.1) upwards. If you have an older version, +upgrade to sendmail 8.9.

-Basically you need to use the "check_*" rules in sendmail. -These are rules introduced since version 8.8.2

+Stock sendmails can now do anti-spam exclusions based on a database of +filter rules. The human-readable form of the database is at +/etc/mail/deny. The database itself is at +/etc/mail/deny.db.

-The idea is to generate a list of domains and addresses that are placed into -a file - I call mine "sendmail.rej" and you place just one domain -or email address on each line. During the SMTP transaction, this file -is checked and if there is a match, the message is refused, with -a suitable "Service not available" message sent back to the sender.

- -With the feature enabled in fetchmail, the mail is simply deleted, -with no further processing.

- -The only drawback when blocking spam with fetchmail is that you -do not get the satisfaction of sending an error back to the sender.

- -To actually use the check_mail rules in sendmail 8.8.2 or better, -you need to know how to generate a sendmail.cf file from the m4 -config files distributed with sendmail.

- -The actual rules can be found at the following URLS:

- - -http://www.informatik.uni-kiel.de/%7Eca/email/check.html

- -This one is by Claus Aßman, who has documented more of sendmail then -I can digest! - -Remember, when copying these rulesets off the web, that there are tabs -embedded in them, that may not be preserved. You must reintroduce -these tabs into the rules to make them work properly.

- -Once you have your ruleset in place, and have generated a nice sendmail.cf -file, and the list of blocked sites, try telneting to your -SMTP port to test it, and send a message with a blocked address in it.

+

The table itself uses email addresses, domain names, and network +numbers as keys. For example,

+
+spammer@aol.com         REJECT
+cyberspammer.com        REJECT
+192.168.212             REJECT
+
+

would refuse mail from spammer@aol.com, any user from +cyberspammer.com (or any host within the cyberspammer.com domain), and +any host on the 192.168.212.* network. (This feature can be used to +do other things as well; see the sendmail +documentattion for details)

-You should see a message similar to:

+To actually set up the database, run 

-     "571 unsolicited email is refused"
+makemap hash deny <deny
+in /etc/mail.

-Next, if you have access to a host that you can send mail from, that -is not your mail host, add that host to your spamlist and -restart sendmail.

- -Send a message to your mailing address from that host and then pop off -the message with fetchmail, using the -v argument. You can monitor -the SMTP transaction, and when the FROM address is parsed, if sendmail -sees that it is an address in spamlist, fetchmail will flush and -delete it.

+To test, send a message to your mailing address from that host and +then pop off the message with fetchmail, using the -v argument. You +can monitor the SMTP transaction, and when the FROM address is parsed, +if sendmail sees that it is an address in spamlist, fetchmail will +flush and delete it.

Under no circumstances put your mailhost or any host you accept mail from using fetchmail into your reject file. You will lose mail if you do this!!!

-The check_ rules work, and they work well. Coupled with fetchmail's -ability to respond to the appropriate error messages, you can be assured -of never seeing a spam from any address you put in the reject list.

- -The only thing that is missing, as mentioned previously, is the ability -to allow sendmail to process the message further and generate an error -message to the sender.

-

T1. How can I use fetchmail with sendmail?

@@ -2089,7 +2064,7 @@ Re-ordering messages is a user-agent function, anyway.

Back to Fetchmail Home Page To Site Map -$Date: 1998/07/25 18:15:58 $ +$Date: 1998/07/31 20:56:28 $

Eric S. Raymond <esr@snark.thyrsus.com>
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