[145923] in North American Network Operators' Group
Re: Outgoing SMTP Servers
daemon@ATHENA.MIT.EDU (Ricky Beam)
Wed Oct 26 17:07:52 2011
To: "Alex Harrowell" <a.harrowell@gmail.com>
Date: Wed, 26 Oct 2011 17:06:57 -0400
From: "Ricky Beam" <jfbeam@gmail.com>
In-Reply-To: <fc0d6d88-128a-455e-9c70-76957ffd6220@email.android.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Tue, 25 Oct 2011 15:52:46 -0400, Alex Harrowell <a.harrowell@gmail.com>
wrote:>
> Why do they do that?
You'd have to ask them. Or more accurately, you'd need to ask their
system integrator -- I've never seen an "in house" network run like that.
(and for the record, they were charging for that shitty network access.)
Bottom line: Blocking port 25 (smtp) is undesirable, but necessary for a
modern consumer internet. (Translation: It f'ing works.) This is the ISP
saying, "You aren't a mail *server*." MUA's (mail clients) should only be
connecting to specified MSA's or MTA's (mail *servers*). They should
never be connecting to random MTA's (presumably for direct delivery, which
is the job of an MTA not MUA.) The only people who can effectively police
this is the ISP. Individual mail server admins and RBL maintainers can
only guess and be reactionary, which is often wrong, still lets spam
through, and becomes stale rather quickly.
--Ricky
