the mail.msu.edu project

To accomplish spam flagging, the mail.msu.edu system is using the free software package, SpamAssassin. SpamAssassin tests each email message against its rulebase, giving each message a total score which corresponds to that message's probability of being spam. For more in-depth information regarding SpamAssassin visit their homepage.

A nice feature of SpamAssassin is that it allows add-on modules. The mail.msu.edu system utilizes the Spamhaus Block List(SBL) plugin to generate more accurate spam scores. Spamhaus is an organization that aggresively maintains a realtime database of known spammers and their internet domain names. The SpamAssassin SBL module examines a message to see if it is from a domain listed in the SBL database. It then uses this information to create a more accurate spam score for each message it examines. For more information see the SBL homepage.

Another SpamAssassin plugin that the mail.msu.edu system uses is the Spam URI Realtime Blocklist(SURBL). The SURBL examines the body of a message looking for links(URIs) contained in its database of known spammers' URIs. It then uses this information to create a more accurate spam score for each message it examines. For more information see the SURBL homepage.