Code Read

INTERNET SERVICE PROVIDERS are trying to block spam under several new initiatives. For example, Yahoo and e-mail management firm Sendmail are testing DomainKeys coding, with an eye toward sharing the technology with other ISPs. The program attaches a coded “signature” to the header of outgoing e-mail messages; receiving systems validate the code, or reject the e-mail. This prevents spammers from using fake addresses, but it could block legitimate e-mail from marketers unless the system is widely adopted by ISPs.

America Online is testing “Sender Permitted From” technology that ensures an e-mail with an AOL return address really came from an AOL user.

Microsoft Corp. and anti-spam software firm Brightmail are collaborating on Microsoft Caller ID for E-mail, which identifies actual senders, then rates their reputation for sending spam or legitimate e-mail. “With the measures that spammers are taking today to disguise themselves and trick spam filters, the anti-spam fight is a continuous one,” said Brightmail President-CEO Enrique Salem in a statement.

And yet anti-spam efforts such as these tend to block legitimate e-mail messages with “alarming frequency,” says Jed Weissbluth, managing partner of online marketing firm Ascent Marketing Partners, Chicago. “Instead of taking a scalpel to the problem, ISPs block everything that looks suspicious — and that net has gotten bigger.”