Most big-time e-mail clients offer some kind of spam filtering, as do many antivirus packages. There are also standalone spam-stoppers out there; as it happens, one of the best we've tried is also free. It's called Spamihilator, short for spam annihilator, and seems to sound best when pronounced "spam-EYE-uh-lator." It's a brainy e-mail filter that stands between your e-mail client and your account's connection, scanning incoming messages and sorting out the spam. It learns as you use it, with a little help from you. It supports plug-ins, POP3 and IMAP accounts, and secure connections.
Spamihilator's installer automatically identified all our e-mail clients but one, and we were able to configure it manually. We chose to associate Spamihilator with Mozilla Thunderbird. We right-clicked Spamihilator's System Tray icon to access its copious settings, as well as the Recycle Bin, Spam Statistics, and the Training Area. This last item lets you mark recently received email as spam or nor spam. The program studies e-mail for key words and phrases, learning to filter future messages. The app's properties feature a tree view similar to an e-mail client's account settings, and just as numerous, too: There seems to be little you can't configure about how Spamihilator does its job. And it does its job well--too well for casual users who won't bother to set it up or train it properly. We ran Thunderbird, and a small pop-up displayed incoming messages and spam in a counter and progress bar in the lower right corner of our desktop. Spamihilator scanned incoming messages and filtered some into its Recycle Bin, while others it sent to Thunderbird's inbox. In the Recycle Bin, were able to click on any sender and quickly designate them as friends or nonfriends; a good thing because more than a few actual friends had been binned. We cleared them and ran Thunderbird again, and this time the messages from the lost friends appeared in our inbox.
Spamihilator's Bayesian, Link, and DCC filters give it an ability to distinguish spam that we've not encountered before. It adds cutting-edge spam filtering to just about any e-mail client, even some you've probably never heard of.