[ILUG] Postfix, SA and RBL problems

[Niall O Broin]

A while ago I sent this message to the list:

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I use the spamhaus blacklist with various SMTP servers and it works nicely. 
However, recently on a server running Postfix 1.1.11 (yes, I know) it appeared 
to have stopped working properly. I got lots of messages such as this in the 
logs:

Apr 17 00:41:31 pogo1 postfix/smtpd[26325]: warning:        \ 
230.192.141.69.sbl-xbl.spamhaus.org: RBL lookup error:      \
Name service error for 230.192.141.69.sbl-xbl.spamhaus.org: \
Host not found, try again

Note that DNS lookup is working correctly on this box - if I dig for such an 
address, I get NXDOMAIN. Now surely in the normal course of event, this is 
(hopefully) what you'll see more of i.e. failed lookups because the host is 
NOT in the list. So, why is that being reported? Also, in the current logs I 
am seeing NO RBL rejected messages. I suppose it's possible that the spammers 
have stopped sending mail to this server, but I doubt it, somehow.
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Since then, I upgraded the box to Postfix 2.1 (yes, it was about time) and the 
problem appeared to be resolved. However, that was a red herring as the 
problem has reappeared, after I added support for SA to Postfix. This I've 
done with this line added to master.cf:

smtp inet n - y -  - smtpd -o content_filter=procmail:filter

and this in /etc/procmailrc:

SENDER=$1
SHIFT=1

:0 hbfw
* < 256000
| /usr/bin/spamc

:0
| /usr/sbin/sendmail -i -f "$SENDER" -- "$@"


So the bottom line is that the lookups of sbl-xbl.spamhaus.org work fine, but 
not when procmail is used. Any ideas?



-- 
Niall