Michael Tsai has released version 2.1.3 of his spam filtering tool
SpamSieve, which uses Bayesian filtering for better results. The new edition features new menu commands for easy installation of plug-ins and AppleScript support files, faster processing of messages, keyboard shortcuts for Apple Mail scripts, added support for Outlook Express 5, and more.
This is a free upgrade for existing SpamSieve owners. The full version is US$25; a free trial allows you to check out the software for 30 days or 20 launches, whichever comes first. SpamSieve requires Mac OS X v.10.2.x “Jaguar” or higher (v.10.3.2 “Panther” or higher is recommended) and works with Apple Mail, Emailer, Entourage, Eudora 5.2 or higher, Mailsmith, Outlook Express 5 and PowerMail.