[ietf-dkim] protecting domains that don't exist

[Arvel Hathcock]

 > The question that I haven't seen addressed directly
 > is why it's so important to provide ADSP for domains
 > that don't exist.

Eric explained it pretty well I thought.  We need the NXDOMAIN check so 
that use of arbitrarily selected host name don't immediately defeat  ADSP.

 > Mail filters often do that even though they don't check DKIM and don't
 > check ADSP.

So?  Are you saying that because a practice is already in use it 
therefore isn't a candidate for specification?

 > So what's the point of importing it into ADSP?

The point is so we can make certain that those who aren't currently 
employing the practice will do so and to make sure that the practice 
gets itself into a standards document from this body so that we don't 
have to guess whether it's being used or not.

I honestly don't understand the resistance to something as trivial and 
well understood as an NXDOMAIN check.

Arvel