From Hendrickson Software Components:
Easy to use email filtering, filtered email forwarding, and spam tracing and reporting. Uses Bayesian filter, country of origin filter, embedded links country of origin filter, white list, black list, ignore list filters, easy to import friends list, blocks image spam (including .zip files), filters on mass mailer tag. Fully tested on 64 bit Snow Leopard. Fully AppleScriptable. AppleScript support for Apple Mail, and Microsoft Entourage.