Is DKIM only for boundary MTAs? (was Re: QUERY: Key Server Choices)

[Earl Hood <earl@xxxxxxxxxxxx>]

On July 27, 2005 at 10:21, domainkeys-feedbackbase02@xxxxxxxxx wrote:

> Would you call this a back-door replacement for S/MIME and PGP - since
> presumably the "ends" are likely to be UAs rather than edge servers?
> If so, why burden an edge-protocol, as you put it, with an end-to-end
> requirement?
> 
> The point being, 2) doesn't seem relevant to our task.
> That leaves 1) which shows xmks as an adjunct to DNS rather than an
> alternative.

I'm getting mixed signals with some statements made on this list and
what is mentioned in the DKIM draft.  Some posts to the list tend to
emphasize DKIM for use by boundary MTAs (aka "edge servers") vs MUAs.
However, the DKIM draft explicitly mentions MUAs and that MUAs may
perform signing and verification.

Therefore, I would like to get clarification on where DKIM sits
in the composition to final delivery chain of an email message?

--ewh