Planning Underway for Enhancements to Spam Filtering Service

In an effort to further reduce the number of unsolicited commercial (spam) email messages passing through the campus email servers, planning is underway to enhance the spam filtering service that was first implemented in May 2003. Enhancements include:

  • Temporary quarantine of high scoring messages (available on June 8) Messages scoring 15 points or higher would be sent to quarantine message folders automatically created for all campus email users. Quarantined messages will be saved in those folders for 30 days. Users will be prompted to review those messages periodically.

  • Real-time black list (available on June 8) This feature identifies spam by running a script on campus email logs and identifying the IP addresses from which spam is sent. If a particular IP address sends more than 20 messages identified as spam in at least a 24-hour period and over 85% of messages sent from that address is identified as spam, the IP address is added to the campus blacklist. All messages originating from IP addresses on the blacklist will be rejected by the campus email servers. Those IP addresses will be posted on a Web page.

    Refinements to spam scoring system (available in July)

  • Bayesian filtering: the training process used to distinguish spam from legitimate mail

  • Distributed Checksum ClearingHouse (DCC): identifies SPAM by storing the checksum and number of messages sent.

    For additional information about spam filtering or to set up filtering on your campus email account, see security.ucdavis.edu/spam.cfm.