Those people rely on ISP access. As ISP access gets distributed throughout the world, spam will rise. Paul says the company's plans include opening the rules engine to customers so IT departments can set filters to catch e-mail that isn't strictly spam but is still unwanted, designing a similar service for small businesses and building an antivirus product. A server-based solution that stops viruses at the Internet gateway, as Brightmail does with spam, would give better protection than the currently popular solution of installing antispam software on individual desktops, he says. The spammer doesn't know if the account exists, but sending another message into cyberspace is such a small incremental cost that the gamble is worth it.
Corporations can do keyword filtering to block spam.
With filtering, a rule checks messages as they arrive. The rule works by testing the sender or searching for keywords in the subject. But it's a crude solution, says Giga Information Group Inc. analyst Jonathan Penn, and often either lets through mail it shouldn't or deletes valuable items. In addition to security features, this server-based program blocks messages based on the originating domain and checks for keywords that indicate potential spam. As people have tried to police spamming on the Internet, a few Web sites have been created to educate people on effective antispam techniques.