NIU’s spam fighters waging noble battle

by Joe King

If you are frustrated at the amount of spam e-mails in your inbox, know this: It could be worse. A lot worse.

On a recent day in January, spam blocking measures put in place by Information Technology Services blocked nearly 85 percent of all e-mail sent from off campus to university servers. Even at that, mailboxes were sprinkled with unwanted stock tips, unsolicited cures for baldness and unwelcome ideas on how to overcome (ahem) alleged personal deficiencies.

While that day was something of an extreme example, it is common for university spam filters to block 60 percent of all e-mail sent from outside sources, says ITS Software Support Supervisor Jon Ostenburg, one of nearly 20 university employees who devote at least part of their work day to handling spam-related issues.

In all, more than 200,000 e-mails are blocked on a typical day.

“It’s a back-and-forth battle,” Ostenburg says. “Spammers keep coming up with new tricks, and we keep coming up with ways to block them. It’s a cycle.”

NIU employs three levels of spam filtering.

The first level is a commercial service which typically blocks 50 percent of all mail sent to NIU servers. A second piece of software scans for viruses and forbidden attachment types, snagging an additional 1 or 2 percent. Finally, a third piece of software analyzes who sent the message, what servers it passed through and other factors, then calculates a spam score, with about 8 percent of all messages failing that test.

Despite such efforts, spam still gets through. For instance, the stream of e-mails with nonsensical subject lines users might have seen recently in their in-boxes is the spammer’s way of avoiding many commercial filters. The text of such messages is little more than random words, none of them deemed objectionable by filters.

However, users who view the item as HTML will see an advertisement. For a while, spam blockers were able to use optical scanning software to battle those tactics; spammers then responded by degrading the quality of the image to the point where it was readable by the human eye, but gibberish to scanners. The battle goes on.

By default, all those who use university e-mail systems (such as GroupWise) are subscribed to the most stringent level of screening. A piece of legitimate mail occasionally gets blocked, Ostenburg says, but it is an extremely small percentage.

Those concerned that important messages are being blocked can adjust their personal spam filtering settings at www.canspam.niu.edu. At that site, users can make changes that will allow them to receive e-mail from specific senders that would otherwise be blocked. Users also use that site to block senders who repeatedly get through the system.

The site also provides information on more advanced ways of personal spam handling, and the ITS Helpdesk (753-8100) is always willing to assist with that process.

One tool Ostenburg does not recommend is the Junk Mail handling feature in the GroupWise desktop software. Using that feature accomplishes little, he says.

The blocking it provides is based on things such as e-mail addresses and domains, most of which spammers never use more than once, so blocking is a waste of time. There is also the risk that users might mistakenly block an important sender. “If you use it, be very careful,” Ostenburg says, “and occasionally check your block list to make sure you haven’t inadvertently blocked someone important.”

There are steps that all NIU employees can use to minimize spam, Ostenburg says.

Never respond to spam in any way. In particular, never click on links that invite you to opt out from future e-mail from that address. In all likelihood, it will actually increase the amount of spam sent your way.

Use your NIU e-mail account for official business only. When subscribing to a Web site, for example, never give your NIU address.

Look for repeat offenders. If unwanted mail from a particular company or individual repeatedly makes it to your in-box, use the advanced blocking features at www.canspam.niu.edu.

Manage your listservs. Newsletters and listservs resemble spam to scanning software, so add any such subscriptions to your permit list at www.canspam.niu.edu.

For more information on dealing with spam e-mail, contact the ITS Help Desk at (815) 753-8100.

1-16-07