Spam Filter

[Les Mikesell]

On Tue, 2006-06-27 at 03:11, jdow wrote:
> > 
> > Rejecting the mail during the *SMTP* transaction *never* involves any
> > hosts or addresses mentioned in the message headers.  It is a TCP
> > protocol-level thing only involving the peers: the sending host and
> > your receiving host.  It's impossible to involve a third party.
> > 
> > Of course, that was the point Paul was making.
> 
> That is, of course, the right way to do it. But after being on the
> receiving end of a joe-job in the past I am a little "sensitive" to
> the issue. And SOME people, probably not Paul on second thought (sorry
> it was not first thought, Paul), are a little careless with regards
> to "reject" and "bounce".

If the mail has already been forwarded through a normal
relay, it doesn't matter whether the next hop accepts and
generates a bounce or it rejects with a 5xx status.  The
rejection will force any standards-conforming mailer to
generate a bounce back to the sender - even if the sender
address was forged.  The only difference is that the
reject saves your own machine the trouble of constructing
and trying to return the bounce message.   A lot of
spam-spewing software sends directly though and a
rejection is the end of it.

-- 
  Les Mikesell
   lesmikesell at gmail.com