From Bains Software:
SpamSweep is an advanced bayesian spam filter with a simple, easy to understand interface. SpamSweep seamlessly combines many filtering technologies, including domain and relay blacklists, sender whitelisting, and a bayesian filter to automatically delete spam messages before they're downloaded by your email client.
SpamSweep can notify you when you have new good mail by playing a sound, displaying the new messages in a floating window, or launching your email client.
What's new in this version:
- Compatible with Snow Leopard.
- Improved interface.
- Bug fixes.