BitDefender AntiSpam for Windows Workstations incorporates three different proprietary modules to keep your inbox spam-free: the Whitelist-blacklist, the heuristic filter and the Bayesian (learning) module.

The heuristic filter performs set of tests on all the message components, (i.e. not only the header but also the message body in either HTML or text format), looking for words, phrases, links or other characteristics of spam. The Bayesian filter module classifies messages according to statistical information regarding the rate at which specific words appear in messages classified spam as compared to those declared non-spam (by the admin or by the heuristic filter). White list/Blacklist--crude, but effective. Know your friends, know your enemies. That?s all there is to it.