FYI, the SPAMFILTER HOWTO doc has been revised after installing
the system on my company's production machine.  The production
system has been running for a couple of weeks now, and is doing a
fine job. I consider this doc complete, and accurate.  Following
this HOWTO can provide anyone (with even the most basic *nix
skills) to create an anti-spam mail filter relay server.

http://www.geocities.com/scottlhenderson/spamfilter.html

Scott