Spamassassin Tips

Passive Spam Block List or PSBL is a real-time trap-based DNSBL operated by Red Hat kernel engineer Rik van Riel.  It uses the Open Source Spamikaze in order to build and deploy an IP-based blacklist of spam sending offenders.  PSBL is one of the safest DNSBL's, and has been default in Spamassassin as of version 3.3.0 released in early 2010.

PSBL receives millions of spam every day, and after taking some safety precautions, it lists the sending IP addresses.  Then various organizations can download that list via rsync or query its public servers via DNS.  Accidental listings can be removed at any time through the self-serve interface at PSBL.org.  Otherwise, if an IP address does not send spam to PSBL within 2 weeks, then it is expired and no longer blacklisted.

If you have a sizable quantity of mail delivery, like greater than 20k messages per day, you are advised to run your own caching DNS server as it benefits your Spamassassin deployment in both speed and reliability.  This article describes why it is important to operate your own local caching DNS resolver, and how to enable it on your server.

UPDATE 6/29/2011: If you run sa-update now, it should pick up 1140482 or later and fix this issue.

Due to a bug in the rule auto-promotion system, SEM rules were again mistakenly pushed to the active rules, causing a flood of unexpected DNS queries to this service provider.  A very similar issue happened back in March 2011.  Upstream spamassassin needs to make an emergency sa-update rule update to correct this situation.  Meanwhile, all spamassassin admins should mitigate this issue by adding the following workaround to their local.cf then restarting their spamd.

Today was the official release of Apache Spamassassin 3.3.2.  The primary purpose of this minor release is to fix compatibility with perl-5.12+, but numerous other bugs were fixed.  I made these RPM's for EL5 and EL6 that I personally have been using in production for weeks.  Fedora 14 and 15 updates should be hitting mirrors shortly.

After you have upgraded your Spamassassin, read the SpamTips.org Ultimate Setup Guide to learn how to maximize your Spamassassin deployment effectiveness. Spamassassin sysadmins may be interested in subscribing to this