Michael Tsai has released SpamSieve 2.1, an update to his Bayesian spam filtering utility for popular e-mail clients such as Apple Mail, Mailsmith, Entourage, PowerMail, and Eudora 6. Version 2.1 includes support for Apple Mail POP accounts (Tsai said POP messages can be marked as junk and colored, but due to limitations in the present version of Mail they cannot be moved to another mailbox). The update also offers several other enhancements, all of which can be found here. SpamSieve sells for US$25.