Spam Filtering

Spam Filtering

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, 57% of all incoming messages have been confirmed or suspected as being Spam (for the period June 2 to August 8).

How can you help us?

Please feel free to send us a message at HelpDesk@esf.edu 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 HelpDesk@esf.edu 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.

Status:

June 2, 2005: Filtering of 'known' Spam enabled.

June 8, 2005: Message scoring and filtering of suspected Spam enabled with a high threshold. Only messages that are strongly suspected of being Spam will be filtered via this method. This method works in addition to filtering 'known' Spam.

June 22, 2005: The threshold on the Suspected Spam filter was lowered today in an effort to catch additional Spam messages that have been slipping through our 'known' Spam filter.

July 5, 2005: The threshold on the Suspected Spam filter was again lowered in an effort to catch additional Spam messages. It is likely that no additional adjustments will be made until fall 2005.

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

SU Spam FAQ

Related information:

ESF Electronic Mail System Policies


	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.