When Microsoft announced it was overhauling its Hotmail email service with new features last month, one of the enhancements was support for Domain Keys Identified Mail, or DKIM. It was a significant move for Microsoft - and the authentication standard - as John Scarrow, general manager of safety services at Microsoft explained.  "A lot of people felt like Microsoft was biased, only doing SenderID because that's the one we had pushed early on,” he said, via eWeek. “We think it’s the right thing to do for the industry. We think it will encourage more people to sign their mail with DKIM.”

A security standard that verifies the sending domain through encryption, DKIM is rapidly gaining popularity at ISPs such as Gmail and Yahoo, according to Eloqua. In fact, email is not eligible to be added to the Yahoo feedback loop without it. Other ISPs have confirmed that they are making significant investments in DKIM, according to Return Path’s recently released Email Delivery Imperatives guide.

One reason they like it is because it uses public-key cryptography to authenticate the domain name that signed the message, making "DKIM more useful than other types of authentication, where the best that can be done is to relate an email message to the IP address that sent it," Return Path said.

IP Authentication Still Alive

If a marketer does adopt DKIM, however, it still has to maintain IP-based authentication tools as well, says Rick Buck, vice president of privacy and ISP relations for e-Dialog (via Chief Marketer).  "The e-mail receiving community has not yet adopted DKIM to the same degree as it has IP-based reputation management schemes, though many expect it to do so in the next 12 to 24 months."

For more details, see Special Report: What Marketers Need to Know About Domain Reputation.