Please watch your followups, as this message is sent to multiple lists.

The purpose of this message is to clarify my plans for any deployment of the Sender-ID specification in Courier (http://www.courier-mta.org).

Microsoft has made certain patent claims on the Sender-ID specification. Microsoft has issued the IPR disclosures and royalty free license required by the IETF. It appears that IETF's contemporary policies do not prevent the sponsor/advocates from including patented IP material into standards-track specifications, without even requiring the sponsor to actually enumerate and identify their intellectual property; a mere claim of the existence of some nebulous IP rights is sufficient, which can be revealed at any point in the future, at the sponsor's discretion.

The current development version of Courier implements the original SPF-classic specification, that predates Sender-ID. This will be rolled into a forthcoming release. I'm quite pleased with the results so far -- there are a lot of classic SPF records in existence, as witnessed by my mail logs :-)

It will not be possible for me to implement Sender ID in Courier. Courier is licensed under the GPL. The FSF already flatly stated that Microsoft's IP license is not GPL compatible. I reviewed the most recent version of Microsoft's proposed IP license, and I've reached the same conclusion. For this reason Sender ID cannot be implemented in Courier; Courier's implementation will be limited to the unencumbered SPF-classic.