Re: [Exim] Exiscan using reject behaviour

On Sat, 19 Oct 2002, Marc MERLIN wrote:

> On Sat, Oct 19, 2002 at 10:38:08AM +0100, Dr Andrew C Aitchison wrote:
> > Hmm. Rejecting viruses at SMTP time instead of accepting them and then
> > bouncing them does have this wrinkle.
> >
> > Remote senders of viruses aren't a problem, since their messages
> > will have come through their MTA, which can generate a sensible
> > rejection message.
>
> Actually it is a problem you don't want to bounce the message yourself
> if you can avoid it.

With respect, I think you're presenting the right argument but against
the wrong targets. We all seem to agree that you don't want to bounce
the message yourself.

> The reason is that when the envelope from has been faked,

Sure - but that's the responsibility of whatever offered you the mail,
if you reject at SMTP time. It's not your job to second-guess what
_they_ might do when _you_ reject it. (In an ideal world they
wouldn't have allowed it to reach you in the first place...)

You _could_ accept it silently and drop it on the floor. That would
seem to offer some short-term benefits, but I don't think it would be
proper, in the Great Scheme of Things. I'm real glad that we have a
feasible way of rejecting stuff at SMTP time. If the sender then goes
and does something stupid with our answer then I'd like them to fix
that, sure - but it's not my responsibility.