What the Spam Filter Does

Mark Bering's picture

Once you begin to use the spam firewall, there will be three noticeable changes:

  1. Less spam, or unwanted email
  2. You will begin to receive a periodic "[email protected] Spam Firewall" quarantine message from the address [email protected]
  3. Messages that the system evalustes as potential spam will be quarantined so that you can examine them, and make a determination.

You will have your own unique quarantine mailbox. Follow the link in the email to your account. From this mailbox you can adjust the settings on your account.

Enforcing anti-spoofing rules

E-mail spoofing is the forgery of an e-mail header so that the message appears to have originated from someone or somewhere other than the actual source. Distributors of spam often use spoofing in an attempt to get recipients to open, and possibly even respond to, their solicitations.

In an effort to combat spam more effectively, we are enforcing anti-spoofing rules on the [email protected] spam filters. This is being implemented slowly, starting with the smaller email domains on the system, e.g., and applying this policy to one domain at a time. As spam continues to get more aggressive and pervasive in nature, the steps we take to address it have to evolve to ensure the stability and viability of the [email protected] service.

To prevent interruption in being able to send and receive mail when using the POP or IMAP protocols, verify that you are using the supported configuration settings published at, /services/email/tutorial/ucsf-email-pop-and-imap-settings?page=5.

How [email protected] spam filtering classifies spam email

  • Blocked by the system: This is email that is unquestionably spam; sent from known egregious spam sites. It is blocked from your account and deleted. You will never see these messages.
  • Blocked by the customer: This is email that is blocked based on your own personal settings. Emails that are blocked by customer settings will not appear in your account and will be deleted.
  • Quarantined: This is email that is likely to be spam and is filtered into a separate quarantine mailbox that you are notified of once per day (at 10:30 a.m.). You will only receive a quarantine email alert when new mail has been quarantined.
  • Not filtered: Email not caught by the new spam settings listed above will arrive unfiltered in your mailbox. It is our goal that the spam filter system will ensure that these messages are 95% legitimate and expected.

The more restrictive your settings in your personal account the more messages that will be captured by the spam firewall. Use caution when ramping up personal settings. Settings that are too restrictive can lead to "false positives," and to the blocking of valid messages from the system. Messages that are blocked are unrecoverable.