Host of Spam Groups Is Blocked From Internet Access.

The volume of junk e-mail sent worldwide may have dropped drastically yesterday after a Web-hosting firm, identified by many in the computer security community as a major host of organizations engaged in spam activity, was taken offline.

McColo, a San Jose Web-hosting company that, according to computer security experts, serves as a U.S. staging ground for international firms that sell a variety of items, including counterfeit pharmaceuticals and child pornography, ceased operations after two Internet providers blocked Web access.

SecureWorks, an Atlanta security-services provider, estimates that McColo was responsible for 75 percent of all spam sent in the United States each day.

Blocked From Internet Access.