Autor: Edgar Lovecraft Fecha: A: exim-users Asunto: Re: [Exim] Using IMAP protocol to SEND email ??
Matthew Byng-Maddick wrote: >
> On Sun, Apr 25, 2004 at 04:11:08PM -0500, Edgar Lovecraft wrote:
> ..[snip]... >
> > Duh... That is what the standard is for ;)
> > Anyone who implements a very poor MSA setup deserves what they get.
>
> You're missing my point. The reason we have closed tcp/25 in various
> places is to try and stop arbitrary delivery from within networks. If
> people are implementing 587 allowing non-authenticated local delivery,
An open relay, is an open relay, is an open relay, is an ....
> then eventually, these networks will be forced to block tcp/587 too.
Nope, i disagree, there would be no more blocking of this than there would
be for blocking outbound TCP 137/138 (Netbios ports) on ISP netblocks.
> So it doesn't just affect them (to deserve what they get), it affects
> all of us.
No it does not, as those servers would be easily identifiable if you are
suggesting that they would be sending to much UCE/UBE, in which case,
they deserve what they get, and it does not at all effect the rest of the
Inet. Also, "SMTP Submission" is not about using TCP 587, or 25, or 8190,
or any other port, "SMTP Submission" is the WAY that a message is inserted
into the MTA data stream (data stream being a generic transport statement).
An open-relay on ANY port is just that, an open-relay, not an MSA server.
<FROM_RFC_2476>
3.1. Submission Identification
Port 587 is reserved for email message submission as specified in
this document. Messages received on this port are defined to be
submissions. The protocol used is ESMTP [SMTP-MTA, ESMTP], with
additional restrictions as specified here.
While most email clients and servers can be configured to use port
587 instead of 25, there are cases where this is not possible or
convenient. A site MAY choose to use port 25 for message submission,
by designating some hosts to be MSAs and others to be MTAs.
</FROM_RFC_2476>