Will connect with your ISPs (Internet Service Provider) mailserver (via POP3) and check each email message found there - prior to your downloading with your email client program (such as Eudora, Inbox, Exchange, Outlook Express, etc). It compares the information in the message with your valid email addresses (since most spammers, it seems use the TO field of the message as something other than your address), and against an extensive listing of known spammers (currently nearly 4,000 are included with SpamEater). If the message is found not to be to one of your valid addresses (which you define), or if a match is found against the list of known spammers, then the message is deleted from the mail server. You can then connect with the mail server using your email client program and download only those cleared messages. All spam will be gone!