On November 24, 2003, Academic Services and Emerging Technologies (ASET), a unit of Information Technology Services (ITS), began its trial evaluation of spam filtering on Penn State's e-mail servers. This spam filtering evaluation allowed ITS-operated Penn State e-mail servers to reject spam and minimize the impact to University networks and computers. Many "spammers" deliver their spam by using third-party resources without permission. The approach in this evaluation filters e-mail based on its origin rather than its content. For additional details surrounding the trial, please refer to the trial announcement at http://aset.its.psu.edu/spamfilter.html.
Trial Results - A Snapshot
Since the trial began on November 24, up to 900,000 e-mail messages have been rejected per weekday. While the trial has demonstrated positive effects, statistical and anecdotal evidence show that spam has increased significantly throughout November and December, in part because spammers are constantly creating new methods to evade anti-spam efforts.
Dispelling Some Myths
Many believe that spammers use Penn State Directory Services, which uses Lightweight Directory Access Protocol (LDAP), to "harvest" faculty, staff and student e-mail addresses because the directory is available for public access. It is important to note that LDAP is monitored on a daily basis for "data mining" activity and it has not been data mined from outside Penn State. If activity within Penn State is observed, the network administrator for the network from which the activity has been noticed will be contacted immediately.
In addition to the precaution above, the online version of Penn State's directory at http://www.psu.edu/directory/ limits queries to fifty per day per IP address. Likewise, an authenticated directory search page, available only to users with an active Penn State Access Account, is provided to help prevent this kind of activity.
Interestingly enough, a search via Penn State's search engine on the criteria @psu.edu yeilds 1.2 million hits. For many spammers, this is a good place to start. In addition to filtering efforts at the server level, users can elect to remove e-mail addresses from Web pages as appropriate.
On the Horizon
ASET plans to explore new and alternative methods for spam filtering. In addition to continuing the current trial, other methods such as opt-in filtering will be tested. Announcements will be distributed to notify the Penn State community prior to any pilots.
Help/Resources
Questions, problem reports or requests for assistance may be directed to the ITS Help Desk at helpdesk@psu.edu.
