ISP Earthlink will soon begin testing new e-mail security technology, including Microsoft's recently released Caller ID technology, a company executive said.

Earthlink will be experimenting "very soon," with "sender authentication" technology including Caller ID and a similar plan called Sender Policy Framework (SPF). The Atlanta-based ISP will be evaluating other e-mail security proposals as well, but is not backing any specific technology, said Robert Sanders, chief architect at Earthlink.

Plans to secure e-mail by verifying the source of e-mail messages have garnered much attention in recent months, as the volume of unsolicited commercial e-mail, or spam, has swelled and the number of Internet scams has increased.

Spammers and Internet-based criminals often fake, or "spoof," the origin of e-mail messages to trick recipients into opening them and trusting their content. Sender authentication technologies attempt to stop spoofing by matching the source of e-mail messages with a specific user or an approved e-mail server for the Internet domain that the message purports to come from.

So far, Earthlink has stayed out of the sender authentication fray while Web-based e-mail services, including Yahoo and Hotmail, and major ISP America Online (AOL), have all backed slightly different sender authentication proposals.

Yahoo is promoting an internally developed technology called DomainKeys, that uses public key cryptography to "sign" e-mail messages. AOL said in January that it is testing SPF for outgoing mail, publishing the IP addresses of its e-mail servers in an SPF record in the DNS. Finally, Microsoft-owned Hotmail is publishing the addresses of its e-mail servers using that company's recently announced Caller ID standard.

Earthlink believes that sender authentication is necessary, and is prepared to support multiple sender authentication standards if necessary. However, the company hopes that one clear winner emerges from the field of competing proposals, Sanders said.

"I don't think it's unlikely that we'll see two or three coexisting proposals go into production. We had hopes that they would be able to merge, but I think at this point each standard adds a different function, and we're unlikely to see a merger," he said.

The IDG News Service is a Network World affiliate.