Microsoft’s Sender ID rated incompatible to Open Source

Microsoft's Sender ID solution to spam looks intriguing, and until recently, it seemed destined to become an Internet standard. In brief, Sender ID is designed to ensure that e-mail originates from the Internet domain it claims to come from. It accomplishes this by basically validating a sender's server IP address, and in the event that there's a mismatch, e-mail will be scored as likely spam. Of all of the proposed plans available so far, Sender ID is the strongest, and even the possibility of a an intellectual property lawsuit has done little to taint its reputation.

Indeed, if the framework is looking less appealing right now, it's only because some say that Microsoft's licensing terms are incompatible with Open Source. Today the Apache Software Foundation has rejected Sender ID, arguing that while the license is royalty free, it is incompatible with Open Source, and thus the foundational properties of the Internet.

The current Microsoft Royalty-Free Sender ID Patent License Agreement terms are a barrier to any ASF project which wants to implement Sender ID. We believe the current license is generally incompatible with open source, contrary to the practice of open Internet standards, and specifically incompatible with the Apache License 2.0. Therefore, we will not implement or deploy Sender ID under the current license terms.

Microsoft waited until the last minute to unveil their license, and while the Internet Engineering Task Force found it acceptable, certain provisions in the license caused many potential adopters to reconsider their interest in the framework. Microsoft insists that anyone who uses Sender ID agree to a license that prevents them from making changes to the framework and redistributing it, as many in the open source community are wont to do. Developers would also need to obtain a license directly from Microsoft to even use the IP, which is burdensome and some would argue rather pointless. Microsoft sees the sub-licensing as a way to protect itself from IP lawsuits down the road:

In order to promote Sender ID, Microsoft is pleased to offer its necessary Sender ID patent rights on a royalty-free basis but only to those who are also willing to make their Sender ID patents available on a reciprocal royalty-free basis. The license is also important to Microsoft for defensive reasons. The reciprocity provisions and the ability to reserve defensive rights for Microsoft?s implementations of standards are very important elements in our decision to contribute technology to standards.

Additionally, Microsoft claims to have patents relating to Sender ID, but those patents have not been disclosedsomething which makes many people rather nervous.

Open source advocates are calling on Microsoft to revise the license and remove these restrictions. In the view of the advocates, Microsoft should simply release the framework to the wild, and allow it to become a standard upon which the community as a whole can build upon, much like already existing standards, such as SMTP, POP, IMAP, and all the other things that dominate the e-mail arena.

The good news is that Sender ID was already based, in part, on Pobox.com's Sender Policy Framework, which is still free to use and implement. Keep this in mind the next time someone asks you to define irony.