From: Ned Freed <ned(_dot_)freed(_at_)mrochek(_dot_)com>
You seem to be of the opinion that fallback behavior should be extended to
AAAA, and you seem to be the first one to express that opinion. (I myself have
no opinion on how to resolve this other than believing it has to be resolved -
the present ambigiuty is unacceptable.)
As a private person using the "A record only" way of receiving mail, I
find it useful.
But, the point supporting the stand that it should work for AAAA is:
If something works and is defined with IPv4, then the same thing
should always work exactly the same way, when IPv4 is replaced
The goal should be to make IPv4 and IPv6 easily replaceable anywhere,
whithout any reduced functionality.
IETF mailing list