John Nemeth <jnemeth@cue.bc.ca> writes:

> } We should perhaps deny relaying and perhaps also accepting mail from
> } hosts that have no valid mx or such.
> 
>      Absolutely NOT, this is completely bogus.  MX records indicate
> machines that are intended to receive mail, NOT one's that are
> intended to send mail.

Perhaps he means "valid return envelopes"

--Michael