Andy Sullivan

WASHINGTON: Internet portal Yahoo Inc. released an e-mail standard that prevents "spam" marketers from hiding unwanted messages behind legitimate e-mail addresses.

The technique, if widely adopted, could help Internet providers more easily block the unwanted bulk messages that currently account for up to two-thirds of all e-mail traffic.

Yahoo's proposed standard, known as DomainKeys, would embed outgoing messages with an encrypted digital signature matched to a signature on the server computer that sends the message.

Internet providers could check the signatures on incoming messages and block those that do not match up.

The procedure would be invisible to regular e-mail users because e-mail providers would implement it, Yahoo said on a Web page describing the standard at (http://antispam.yahoo.com/domainkeys).

Internet providers deploy a barrage of filters to weed out spam and large providers like Time Warner Inc.'s America Online block up to 2.5 billion spam e-mails each day.

The technique could also block fraudulent "phishing" attacks, in which scam artists attempt to collect credit card numbers and other sensitive information by posing as companies like Citigroup and eBay Inc., Yahoo said.

DomainKeys, first announced last December, is one of several attempts to help legitimate messages stand out from the flood of spam.

Microsoft Corp.'s Hotmail and MSN services recently adopted a "whitelist" program by IronPort Systems Inc. that would allow legitimate marketers to put money up front if they wish to evade spam filters. Microsoft has also said it is working on another technique to verify e-mail.

Such techniques rely on widespread adoption for effectiveness. Yahoo said it had submitted DomainKeys to the Internet Engineering Task Force, a standards-setting body, and will allow developers to implement it for free.

Sendmail Inc. also has agreed to incorporate the technology into its e-mail software, Yahoo said.

A Yahoo spokeswoman was not immediately available for comment.

©Reuters