Server-based tools can spam, block viruses

As our professional lives become more and more dependent on electronic mail services, it becomes worthwhile to make sure the time spent sifting through messages is used wisely.

Many relevant messages get lost in waves of unsolicited commercial e-mail, known as spam. Even addresses used exclusively for business or private correspondence are susceptible to persistent spammers.

One of the methods used to generate lists for junk e-mail involves a program designed to search online directories—Penn’s own online directory, for example—and pick up addresses. Another possibility is that addresses, once found, are catalogued and sold, proliferating on a variety of routinely used contact lists.

Penn’s Information Systems and Computing division suggests that users register their address with the Direct Marketing Association E-mail Preference Service (, which enables addresses to be removed from the mailing lists of over 4,500 DMA corporate members.

For pobox, dolphin and other e-mail domains hosted by ISC, a new server-based spam filtration program is available. The system uses SpamAssassin to collect and organize flagged junk mail into a separate “caught mail” folder. Most filtering programs assign point scores to certain traits, which include subject headers in all capital letters or free or low rate offers in the message. If the point total is greater than a pre-assigned amount, the message will be sent to the “caught mail” folder.

Often, valid e-mails are tagged as “caught mail” along with spam, requiring the user to manually sift through a list of junk to find the few relevant pieces of information. ISC cautions any potential users enlisting in the program to be aware of falsely tagged messages, a tradeoff with any filtration system.

Users should also test which level of filtration intensity suits them best, as well as check “caught-mail” on a weekly basis due to a semi-monthly dump schedule. Interested e-mail users should visit the Spam Filtering Services page ( and select the Account Services link.

Other schools and centers that run e-mail servers, such as SAS and Wharton, are increasingly providing similar spam filtering to their users.

E-mail is also home to the bulk of virus, or malicious code, transport. Messages not initially flagged as spam may still be malicious. It is very possible for a message to pass all spam tests, yet have a link within it that will download harmful commands to the host computer. Because of this, any incoming or outgoing messages on an ISC mail server are scanned by the remote off-site vendor, MessageLabs. ISC assures users that the method is effective yet still conforms to the University’s privacy and security policies.

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Originally published on November 13, 2003