Thursday, February 25, 2021

False Positive

Symantec Brightmail, ESF's Spam filter, will falsely identify an email message as Spam only once in every one million email messages. For ESF, this equates to one false positive every 2 to 3 months.

SU Spam

Syracuse University may receive as many as 1,000,000 email messages a day. Up to 75% of this is Spam.

ESF began central Spam filtering on June 2 of 2005. The system used at ESF is Symantec's Brightmail AntiSpam. This system uses Multi-layered spam prevention and employs multiple filtering technologies, including spam signatures, heuristics, reputation filters, language identification, and other proprietary methods. The Spam detection rate for ESF users should reach 95% once the system is fully deployed.

ESF uses the same Spam filtering software as Syracuse University. If you are an ESF employee with an SU email account, your email has been filtered with this software (by SU) since the beginning of 2004.


How are we doing?

Since the Spam filter was enabled on June 2, between 50% to 80% of all incoming messages have been confirmed or suspected as being Spam.

How can you help us?

Please feel free to send us a message at and let us know how the new Spam filter is working. When sending us a message, please indicate whether the filter is 1) helping your particular situation or not and 2) give us an estimate of the percent reduction in Spam since Thursday, June 2 when the filter was turned on.

If you feel that you have missed some legitimate email...

If, by chance, you feel that you have missed legitimate email since the filter was turned on (June 2), please send an email to and let us know 1) Who the message was supposed to be from (email address) and 2) The approximate date and time that the message was supposed to have arrived. This may require that you use a different form of communication with the actual sender of the lost message to find out the specifics. NOTE: It is highly likely that any message removed as Spam will note be recoverable.


For answers to common questions about Spam filtering,
please see the following from the CMS Web site: 

Related information: ESF Electronic Mail System Policies