Spam Terrier sits between your email server and your email client, working as a powerful filter to prevent all those spam messages from reaching your inbox. Although we didn't have the time to test it thoroughly (it would have taken days to check its accuracy) we certainly could see that this is a very polished and promising tool that can help you in your personal battle against unsolicited messages.
Spam Terrier is seamlessly integrated into your e-mail client as a toolbar from which you can mark messages as spam or non spam. The program does require some prior training but this can easily be done by means of a wizard and the messages you already have in your inbox. The program also enables you to create white and black lists (for approved and banned senders respectively) as well as decide what to do with spam messages.