I finally added DKIM documentation to the spec. We can release now :)
As for the debate about dropping Domainkeys (DK): I've not changed my
mind about this. Those who want to continue running their present setup
can either
a) stay with 4.69 for the time being.
b) perform Domainkeys signing or verification with external tools.
In any case, I'll not spend time to bring DK back. It just feels
pointless. I'm not a fan of historical reenactments. Besides, there
wasn't much distro support of the feature anyway. That just leaves the
usual bunch of self-compilers that have to cope. I think they can.
