Integrating Spam Assassin with your Mail Transfer Agent.

Documentation Pages on MTA Sites

Here are links to places that document how to integrate SA with your Mail Transfer Agent.

[http://www.exim.org Exim] - [http://www.exim.org/exim-html-4.50/doc/html/spec_40.html Content Scanning] with Spamassassin Documentation Page.
[http://www.stalker.com CommuniGate Pro (CGP)] - Try CGPSA, available at http://www.tffenterprises.com/cgpsa/