Alessandro Vesely writes:
According to Wikipedia, http://en.wikipedia.org/wiki/DomainKeys
the GPL option is there "for the purpose of the DKIM/IETF Working Group".
That note has been added to the wiki on 21:07, 12 January 2006 by an
anonymous user connecting from 66.228.162.107 (newspend-mac.corp.yahoo.com).
The DomainKeys Patent License Agreement is still not mentioned in
http://www.gnu.org/licenses/license-list.html
Well, this certainly removes that showstopper.
However, I'm concerned about that "and no other version". GPLv3 should
come in a few months and Courier's Copyright holder may want to use it.
Then, there will still be an incompatibility: would the DomainKeys
Identified Mail (DKIM) addition have to be reverted in that case?
These are all valid points. I don't think I want to implement Domainkeys
directly, but rather link to an external library that implements the whole
thing. The external library can be GPL2-ed, which will probably be enough,
and let someone else worry about these issues. And if nobody wants to do a
GPL2-ed library plug-in, that's going to be that.