SpamAssassin is a computer program released under the Apache License 2.0 used for e-mail spam filtering based on content-matching rules. It is now part of the Apache Foundation.

SpamAssassin uses a variety of spam-detection techniques, that includes DNS-based and checksum-based spam detection, Bayesian filtering, external programs, blacklists and online databases.

The program can be integrated with the mail server to automatically filter all mail for a site. It can also be run by individual users on their own mailbox and integrates with several mail programs. SpamAssassin is highly configurable; if used as a system-wide filter it can still be configured to support per-user preferences.


  1. Find out whether the MTA is complaining about SpamAssassin:
    % sudo tail -f /var/log/maillog
  2. If necessary, restart SpamAssassin:

    % sudo /usr/local/etc/rc.d/sa-spamd stop
    % sudo /usr/local/etc/rc.d/sa-spamd start

  3. If necessary, restart the spam-scanning milter:

    % sudo /usr/local/etc/rc.d/spamass-milter stop
    % sudo /usr/local/etc/rc.d/spamass-milter start


  3. "Damn Spam" by Michael Specter. (The New Yorker, Aug 6, 2007.)