SMTP Relays...

From: Doc Shipley <doc_at_mdrconsult.com>
Date: Thu Sep 2 15:44:22 2004

David V. Corbin wrote:

> I have to COMPLETELY disagree. An ISP that blocks OUTBOUND access to ANY
> legal/conforming site or service is being overly restrictive.
>
> If I want to send spam mail I can and will [I DO NOT] by simply running a
> WebService on my external site and talking to that from within the ISP
> domain. Blocking outbound access provides NO benefit to ANYONE [except lazy
> ignorant fools!]

   You just defined most spammers, with respect to network and MTA
configuration. Add to that that a large percentage of spam is relayed
through compromised systems, and blocking outgoing port 25 from a
dynamic netblock is reasonable. It *helps* the spam and Windows worm
traffic a lot.

   Earthlink, Comcast, and several other major providers block port 25.
  I travel quite a bit, and most of the hotel fast-access providers do
the same. My email users (mdrconsult.com accounts) cover all the above
with their home & road accounts, and none need any secondary
configuration. Our relayed SMTP uses SSL/TLS and SMTP AUTH on ports 465
and 587. Nobody blocks those ports, nor are they likely to ever do so.
  My users' mail is secured, my server can't be used as a relay, and
$ISP's self-protective measures are irrelevant.


        Doc
Received on Thu Sep 02 2004 - 15:44:22 BST