[Mimedefang] MX -> 127.0.0.1

[Les Mikesell]

On Tue, 2005-09-13 at 13:33, Jim McCullars wrote:
> >
> > It's unlikely you are talking to the original sender.  Assume a
> > forwarding relay has accepted a copy (as I am doing now), then
> > trying to deliver.  If you give a 5xx smtp response you force the
> > sending relay to construct a bounce.  But you know it's impossible
> > to deliver it.
> 
>    If the forwarding relay cannot construct a bounce, it really has no
> business accepting the mail in the first place.

None of us here can determine that yet or we wouldn't be talking
about how to do it... Isn't it a bit much to expect everyone else to
already be checking?

> Besides, just because you
> cannot deliver a bounce, that doesn't mean the forwarding relay cannot.
> An internal DNS, or mailertable are two ways that it could.

Anyone who has gone to the trouble of poisoning public DNS with an
MX that ends up at 127.0.0.1 really doesn't want that bounce back
so I think we can assume they won't make an extra effort to make it
work from certain machines.  Or, they just want to cause trouble
for others and it becomes your choice to help them or not.

-- 
   Les Mikesell
    les at futuresource.com