[mail-vet-discuss] New draft for review

[Michael Thomas]

John L wrote:
>> On second thought, wouldn't the MX for an address *be* a border MTA 
>> and thus part of the intended recipient's administrative domain?
> 
> Yeah.  That's the place where the message hops from the senders's 
> network to the recipient's network.
> 
>> An intermediate MX could do any authentication it wants, but any A-R 
>> header it adds is not desirable by the receiving domain anyway.
> 
> Sorry, that's just wrong.  My wife has an address at cornell.edu which 
> forwards to an address here.  Since I know the path that the mail takes 
> from Cornell to here, if Cornell added a header and the message arrived 
> via the known path, their header would be quite useful even though the 
> message subsequently made an MX hop to get here.  Ditto for my addresses 
> at acm.org, ieee.org, etc.  For SPF and other path authentication, an 
> A-R from the previous MX would be greatly preferable to the alternative 
> of parsing Received: headers.

Can I suggest that we not use MX? It's got a very specific meaning in
the email architecture, and I don't think that auth-res requires it have
any linkage to the actual hosts listed in an MX record. The draft's
use of the term seems to imply that there is, and I don't think that's
the intent.

		Mike