PreciseMail Anti-Spam Gateway eliminates unwanted spam at the Internet gateway without filtering critical legitimate e-mail messages, producing a large potential cost savings to organizations of all sizes. Its filtering engine is based on a combination of proven heuristic and artificial intelligence technologies. As a result, PreciseMail Anti-Spam Gateway determines whether e-mail is spam instead of passively reacting to known spammers by creating rules that block them after a spam attack occurs.