What can you do about spam--that unsolicited, unwanted junk e-mail? Until now, the best way has been to simply go through your inbox and delete all the spam. But now there's another method: Information Systems (IS) has started an MIT Spam Screening service and web site.
A program called SpamAssassin that IS has installed on the Institute's central post office e-mail servers performs a series of tests on e-mail messages and issues a score based on how likely they are to be spam. The higher the score, the more likely that a message is spam. The score and a YES/NO flag are added to each message's header, which you may have already noticed.
Depending on the type of e-mail client you use (POP or IMAP), you can manage the spam messages in various ways--for example, by having flagged messages automatically filtered into a separate mailbox as they arrive.
The actual contents of your e-mail are not being changed, filtered or blocked; all e-mail sent to you at MIT will be delivered to you. If you do nothing, the only change will be the added headers in your e-mail; you must choose to make a filter in your e-mail client or create a specific IMAP mailbox for any filtering to happen.
The system isn't perfect; distinguishing between legitimate e-mail and spam with an automated algorithm is a challenging problem. Commercial spammers are sophisticated and keep changing their mass mailings to avoid spam detection methods. A few legitimate messages also will be scored as spam, so you should scan through all the spam-flagged messages regularly to be sure any e-mail you want doesn't end up lost amid the spam. You can also customize your "Allow" list in your spam settings to refrain from mistakenly flagging messages from a particular address, as well as your personal spam threshold (the score above which messages are flagged as spam).
(This is an edited version of an article that appeared in the January/February issue of i/s newsletter.)
A version of this article appeared in MIT Tech Talk on March 12, 2003.