What is SpamAssassin?

SpamAssassin is a powerful tool for eliminating unsolicited emails (spam) from your incoming mail. Using a wide range of rules and filtering methods, it accurately detects spam emails. SpamAssassin does not require you to install any software on your computer. Instead, it runs on the server-side, scanning and filtering email before it is forwarded to your mailbox.

SpamAssassin subjects every incoming email to three levels of spam tests:

  1. Header Analysis. Spammers often forge return addresses, and add bogus entries to the headers of their emails. This is done both to fool you into thinking that the email is valid, and to make it harder to determine the actual source of the email. Spam Assassin knows what to look for in these headers, and can quickly identify false, invalid, or misleading information.

  2. Text Analysis. Spam emails often have characteristic styles, phrases, and disclaimers in them. SpamAssassin attempts to spot some of these clues.

  3. Blacklists. SpamAssassin compares each email to the lists maintained on major Real Time Blacklist servers (RBLs). If an email is sent from a domain or server in one of these blacklists, there is a good possibility that it is spam

Each test uses hundreds of rules that indicate whether an email might be spam. Each rule it finds is assigned a "point" value. When the total points of an email exceeds your acceptable limit, the email has a "*****SPAM*****" flag placed in its subject line. These flagged spam emails also have a full spam report outlining the rules effected and the points awarded for each. These reports will appear in either the body or header of the email according to your preference.