John Leslie wrote:
Whether or not we have any consensus that this historical
practice should be deprecated (I would vote YES!),
rfc2821-bis is not, IMHO, the right place to deprecate it.
It could be seen as an unintended chance to keep AAAA out
of this business, because RFC 2821 forgot to mention it.
Admittedly a trick, twisting an unreported 2821 erratum
into a feature, but if it is for a good purpose, why not.
" If no MX records are
" found, but an address RR (i.e., either an IPv4 A RR or
" an IPv6 AAAA RR, or their successors) is found, the
" address RR is treated as if it
That proposal touches the IPv4 fallback. I think we'd need
to split it, IPv4 as is (2821 + 2821bis), IPv6 MAY (because
RFC 2821 did not require it 2821bis should say what we want).
IETF mailing list