Bill Hacker wrote:
> > So lets examine the case:
> >
> > recepients 'a', 'b', 'c' and "fake" 'd'.
> >
> > HELO ...
> > 220
> > MAIL FROM:...
> > 250
> > RCPT TO:<a>
> > 250
> > RCPT TO:<d>
> > 550
> > Connection closed by foreign host.
> >
> > Does the remote side give up on recipients 'b' and 'c' or does it establish
> > a new connection some time later and try them as well as 'a'?
> >
> > RFC2821 (3.9) implies that it will retry:
> > SMTP clients that experience a connection close, reset, or
> > other communications failure due to circumstances not under
> > their control (in violation of the intent of this specification
> > but sometimes unavoidable) SHOULD, to maintain the robustness
> > of the mail system, treat the mail transaction as if a 451
> > response had been received and act accordingly.
> >
> > Hence "remember that a fake address was a recipient and use deny
> > or drop in your pre-data ACL". That way you kill the whole mail,
> > not just one recipient.
>
> Interesting thread. Might I ask, what is the likely effect (if any)
> when one's Exim is configured to neither advertise nor accept 'pipelining'?
I'm not sure that pipelining or no piplining will affect this
transaction materially. Maybe someone else can parse this data out
of RFC2821.
Ian
--
Ian Freislich
