Spam deluge leads to search for silver bullet

Battle promises to be tough

High on the list of unintended consequences for ISPs is losing customers who feel that not all their legitimate mail is getting through.

For Atlanta-based EarthLink, the solution was offering customers a filter, dubbed Spaminator, which blocks 70 percent to 80 percent of spam from user inboxes, and sends them to a "gray folder" that users can peruse to make sure none of their wanted mail has been trapped.

Other e-mail service providers offer the same kind of service. Yahoo, for example, employs its proprietary SpamGuard filter which sends spam to a "bulk mail" folder in user inboxes so customers can still dictate what they think is spam.

In addition to offering SpamGuard to its free e-mail customers, Yahoo offers premium mail customers even more stringent filtering tools. Additionally, the company recently added a "this is spam link" within e-mail messages, allowing them to report an offending missive to Yahoo for future blocking purposes.

"Yahoo has taken a holistic approach to combating spam," said Lisa Pollock, director of Yahoo's messaging products.

The multifaceted approach seems to be working. Yahoo caught five times more spam in November 2002 than it did in January of that year, according to Pollock.

Although the growing onslaught of spam has led some to advocate dire measures such as using white lists, where users only accept mail for senders stored in their address books, this measure seems extreme. Critics of white lists point out that a long-lost friend who digs up someone's e-mail address would never get their well-wishing message through, nor would associates who recently changed jobs, or Grandma, who just managed to get online.

Even black lists, which some ISPs use to block mail being sent from known spammers, are starting to lose their following because they need to be constantly updated and changed.

While Yahoo's Pollock concedes that the growth of spam is a problem, she doesn't believe extreme measures are in order yet.

In fact, Pollock said that part of the apparent spam epidemic could be chalked up to the growth in e-mail users, and additionally, she would like to believe that her company is trapping more spam because its filters are more effective.

But it appears that no matter how much fine-tuning ISPs do to their spam-fighting tools, the danger of blocking wanted mail forces them to keep the gates open just wide enough that a certain amount of spam still gets in.

That's where other methods for fighting spam come into place, such as client-side filters.