DSPAM is a server-side statistical anti-spam agent for Unix email servers. It masquerades as the email server's local delivery agent and effectively filters spam using a combination of de-obfuscation techniques, specialized algorithms, and statistical analysis. The result is an administratively maintenance-free, self-learning anti-spam tool. DSPAM has yielded real-world success rates beyond 99.9% accuracy with less than a 0.01% chance of false positives.
dspam project under new management!
dspam is alive and development continues towards the 3.9.0 release. You can find all the latest info at the dspam website (http://dspam.sourceforge.net/) or over and the sourceforge project pages (http://sourceforge.net/projects/dspam/)