Microsoft, however, could take longer to adopt it, Hoffman said. "I would put them probably as last, because they are really heavily invested in Sender ID," he said.
Hoffman said that DKIM is not hard to implement and that he would be surprised not to see it in the next versions of major email support applications such as IBM's Lotus Notes and Microsoft's Exchange Server.
Miles Libbey, the antispam product manager for Yahoo Mail and a co-author of DKIM, said Yahoo has been using the original DomainKeys on both its inbound and outbound systems. He said Yahoo plans to switch to the new DKIM specs but is not sure when that will happen.
The IETF publication of the specifications, which will later lead to a formal draft and then eventual final approval, is a first step toward much broader adoption, Libbey said. "By having gone through the IETF process and gaining consensus amongst the entire internet industry, we've debugged a few issues that surrounded the original implementation of domain key," he said. "Once you actually have it formalised, you're much more confident that the spec is going to be stable."
Eric Allman, the chief science officer at Sendmail, said the DKIM specification and standard will be very important for users. "I do believe this is going to have a major impact initially on phishing," he said.