The Redmond, Wash., company said Monday it is making the "Sender ID Framework" available under its Open Specification Promise program. That meanswho creates products or services based on the e-mail technology.
The move is part of an effort to promote interoperability among commercial and open-source software products, and among Internet access providers that utilize e-mail authentication, Microsoft said in a statement.
"Users will be able to implement, commercialize and modify Microsoft's patented e-mail authentication technology without having to sign a licensing agreement," it said.
Sender ID is a caller ID-like system for e-mail meant tosuch as phishing. Microsoft has been for a couple of years as a partial solution to junk e-mail. Intellectual property issues around the technology have as a roadblock to adoption.
Microsoft announced the OSP in September, when it said 38 Web services specifications would be. Earlier this month, it was expanded to .
Nearly two years after Sender ID's launch, 36 percent of all legitimate e-mail sent worldwide uses the technology, via about 5 million domains, according to Microsoft data.