FreeBSD6 Unleashed

Filtering Junk Mail with Procmail and SpamAssassin

As a FreeBSD email server administrator, it behooves you to make some attempt to hold back the tide of that nemesis of the Internet: junk mail, or spam. Most modern email client applications provide their own internal spam filtering tools, using techniques such as Bayesian pattern matching and other semantics-based and contextual artificial intelligence tricks that lets users “train” their email programs to better identify spam and shunt it away into a quarantine area. Still, though, these client-side techniques are only part of a complete solution to the spam problem, and another big piece of the puzzle can be provided by you at the server level. If you can prevent spam messages from even getting ...