A recent report indicates that the District's new spam/virus firewall, implemented in December 2003, is keeping millions of nasty emails from reaching the inboxes of District technology users.
From January 2004 through December 2004, approximately 9.5 million messages were filtered. 5.5 million were blocked as spam, and 600,000 of these blocked emails contained viruses.
"Only one-third of the email that comes to the District is considered legitimate," says Tom Roza, supervisor, Systems and Operations. "This is very consistent with what's going on around the world. Two-thirds of all email contains spam or is infected with a virus."
Monthly reports have shown that the District's protection against spam and viruses has increased from 50 percent to 60 percent since the firewall was first implemented. This is due to a firewall technique called "tagging," which enables users to identify which emails that make it into their inboxes are really spam.
"The firewall system puts the keyword 'BULK' into the subject line of the email," Tom explains. "When a user receives an email with this tag, he or she is asked to analyze the email to determine whether it is legitimate. The individual then sends the email to one of two accounts: email@example.com or firstname.lastname@example.org."
At this point, the Systems and Operations staff analyzes the e-mails and establishes new criteria by which future emails will be classified as legitimate or spam.
"Each day the firewall learns new variants of spam so that less comes through marked 'BULK' and more is blocked outright," Tom says. "For example, when we first started tagging email, 10 percent was tagged as bulk. Now we're down to 5 percent."
Because spammers are savvy, a firewall's work is never done. However, the District has greatly reduced the amount of spam and will continue to work toward eliminating even more in the future.