Re: Minor is. It's not a pardigm change

At 23:00 -0400 on 03/31/2008, John C Klensin wrote about Re: Minor 
is. It's not a pardigm change:
> Once that implicit MX record exists, there are fairly clear rules 
> about which address to use for foo.example.com.   To be a little 
> more precise, while the rules are clear, they pretty much leave it 
> up to the sending host and there is no real difference between the 
> traditional choice between the two IPv4 addresses and the newer 
> choice between the IPv4 addresses and the IPv6 one.   The Standard 
> also gives the sender implementation some flexibility about how many 
> of those addresses it is obligated to try.
I disagree with your methodology. If the rule is that incoming MTAs 
(ie: Those MTAs that are supposed to be located via MXs) which listen 
at an IPv6 IPN are REQUIRED to be designed by an MX (ie: You are not 
treated as an incoming IPv6 MTA UNLESS you are pointed to by an MX), 
any implicate MX that is built in the absence of an EXPLICATE MX 
should contain ONLY the A records for that FQDN. Any AAAA records for 
the FQDN are ignored in building the implicate MX.