"Tooms" - a longstanding member of the Clearswift MimeSweeper forums, has published a comprehensive guide for integrating SpamAssassin with MimeSweeper for SMTP (version 5 upwards). This gives you such benefits as:
- Plugins such as DCC, Pyzor, Razor, Fuzzy OCR
- Award winning anti-spam engine
- Well documented, many forums for support
- Open Source (and free)
I would recommend a beefy server for this though, SpamAssassin is known for being somewhat greedy with system resources.
The guide is on Tooms's homepage - here.
