DNS question, null MX records

[vixie at isc.org (Paul Vixie)]

Douglas Otis <dotis at mail-abuse.org> writes:

> If MX TEST-NET became common, legitimate email handlers unable to
> validate messages prior to acceptance might find their server
> resource constrained when bouncing a large amount of spam as well.

none of this will block spam.  spammers do not follow RFC 974 today
(since i see a lot of them come to my A RR rather than an MX RR, or
in the wrong order).  any well known pattern that says "don't try
to deliver e-mail here" will only be honoured by friend people who
don't want us to get e-mail we don't want to get.
-- 
Paul Vixie
KI6YSY