outlook express spam filter

CHICAGO — They are imperfect and often overzealous, but spam filters are still the best way to fight unwanted e-mail, technology companies and privacy advocates said yesterday. At a conference here sponsored by the International Association of Privacy Professionals, people involved in the fight against spam said filtering software remains the most widespread and effective way to keep unwanted e-mail out of in-boxes. Scores of other methods to defeat spam have appeared in recent months, including legislation and changes to the structure of e-mail. "There are other solutions out there, but ... filtering is really the most valuable tool," said Carl Hutzler, director of antispam operations for AOL, the world's largest Internet service provider. Spam is unsolicited commercial e-mail. Spam is often deceptive in nature, and technology analysts have said it costs businesses as much as $10 billion a year in services and lost productivity. AOL said it blocks about 80 percent of all incoming e-mail because it is spam. Several hundred companies have emerged in the past year to offer spam-filtering software for e-mail users and businesses. Most filters search for characteristics common in spam, such as pornographic words. Many filters weed out e-mail sent from addresses that have been put on Internet "blocklists," which attempt to identify spammers. Most major Internet service providers use a filtering system to prevent spam from reaching customers, and some boast of blocking more than 90 percent of unwanted messages. The providers acknowledged yesterday that filters are imperfect, because they fail to block all spam and occasionally block e-mail that customers want. But they insisted that filters would remain the primary solution, because no other method has worked. Legislation designed to regulate spam at the state level has failed to stop senders of unwanted e-mail, according to those familiar with the laws. Congress is close to passing a bill that would ban the most deceptive forms of spam, but technology analysts said it is unlikely to work because spammers excel at hiding their identities. To some Internet providers, filtering is an economic necessity. "We can't accept every piece of mail that comes in," Mr. Hutzler said. "The cost would be prohibitive. Filters and blocklists are obviously necessary for these reasons." Microsoft, which owns the Internet service provider MSN, recently updated its spam-filtering service, which examines each e-mail based on more than 100,000 different attributes. It also uses products from Brightmail, a company that filters out spam to more than 280 million e-mail addresses. Much of the staff at the Microsoft's antispam division is charged with researching and analyzing ways to make spam filters more accurate. "We think filtering is certainly part of our core solution," said George Webb, the division's business manager