[ietf-dkim] Are lookalike domains like parent domains?

[Dave Crocker]

Arvel Hathcock wrote:
>> There are two kinds of "not found" responses in the DNS: NXDOMAIN and
>> NODATA. 
> 
> NXDOMAIN (RCODE=3) means the name does not exist in DNS.  NODATA 
> (RCODE=0 + ANCOUNT=0) means the name is valid but no records of the 
> requested type were found.  We're only interested in the first one.
> 
> So, our side in the debate is not operating from a misunderstanding of 
> DNS as far as I can tell.


I understand the reason for the test to be verifying that the From: field 
address is  (probably) valid.  That's an email semantic questions.

Looking for domain existence, rather than domain use of an email-related DNS 
record, seems like a significantly less appropriate test, given the goal of 
the test.

Why is it sufficient for the domain to have no RR relevant to email, just as 
long as it has some RR?

d/

-- 

   Dave Crocker
   Brandenburg InternetWorking
   bbiw.net