Michael Tsai has released SpamSieve 2.6.3, an update to his popular Bayesian spam filtering utility for email clients such as Apple Mail, Mailsmith, Entourage, PowerMail, Mozilla Thunderbird, and Eudora. The new version offers: various accuracy improvements, particularly for messages with attachments; improved compatibility with pre-release versions of Mac OS X 10.5 Leopard; improved documentation; and more. SpamSieve is priced at US$30 and requires Mac OS X 10.2.8 or later (10.4 or later recommended).