mail filtering based on reverse DNS

[Erik Kline]

> I think rejecting on no DNS for ipv6 is going to be eve more a necessity
> than ever before with all thee IP's being dished out to end users.

Without siding for or against this policy, I would say that the right
time to get this hammered out is rapidly passing.  This is something
that could, IMHO, still be enforced, albeit with some possible pain
for existing IPv6 MTA operators depending on the outcome.  It might
not be too late.

So I'm all for whatever might be needed to decide if it's actually a
good policy that everyone thinks should be the long-term state of
things.  Even though some MTA operators might have some DNS work to
do, I don't see such a policy as being wholly unreasonable.
Sufficient socialization of the policy at RIPE, NANOG, etc could be
done to give sufficient advanced warning.

Setting aside the transition work to get there, is this something the
MTA operating community could agree would be a good end state?