While IP addresses in the U.S. made up just 28% of the spam-sending addresses in a survey by CipherTrust Inc., those addresses sent out much more unsolicited commercial e-mail than spammers from other nations.

A New York man convicted of using the network of Internet service provider EarthLink Inc. to send out hundreds of millions of unsolicited commercial e-mail was sentenced to between three-and-a-half and seven years in prison Thursday, according to Brad Maione, a spokesman for New York State Attorney General Eliot Spitzer.

The goal is to use technology to make it expensive for spammers who send out millions of unwanted e-mail messages, according to a Microsoft researcher.

The lawsuits are among the first filed under a new U.S. law called CAN-SPAM, which went into effect in January.

Microsoft is accusing the defendants of violating a new antispam law by spoofing their domains, routing e-mail through open proxies, deceiving customers with misleading subject lines and failing to include unsubscribe options in their e-mails.

An industry organization representing heavyweight e-mail providers Yahoo Inc., Microsoft Corp., America Online Inc. and EarthLink Inc. released recommendations yesterday for ending spam e-mail.

America Online and Yahoo plan to begin using technology to verify the source of e-mail messages in coming months as both companies work to stop spam e-mail.

The exponential growth of unsolicited junk e-mail -- spam -- is shaking consumer confidence in the Internet and may hamper growth of the e-economy, officials on Monday told a global anti-spam meeting.