Setting up SMTP?

[Paul Howarth]

On Wed, 2004-10-27 at 08:16, Ow Mun Heng wrote:
> May I ask, what do you use the MSA for? I believe it's only for a
> _local_ mail submission.

You're confusing it with the MSP.

MSP: Message Submission Program

This is for locally-submitted mail on your server. sendmail runs using
the submit.cf configuration file, queues messages in
/var/spool/clientmqueue and attempts to deliver the mail on to the MTA
running by default on port 25 of localhost.

MSA: Mail Submission Agent:

A mail server for submitting mail for delivery from other Internet
hosts. Listens on port 587 and will relay mail once the client is
authenticated. Intended for "roaming" users so that they can send mail
from their regular SMTP server wherever they are (including on ISPs that
block outgoing port 25 connections).

> But what is the difference then to just point
> the submission to port 25 default?

Port 25 is the MTA, mainly there for accepting delivery of incoming mail
(but also for relaying out messages originating within the
organisation). The MSA is intended exclusively for submission of
outgoing messages.

> I can understand the usage of MSA is only port 25 is closed and you're
> not running as a mail-hub from internet.

I use my MSA all the time. I never have to change mail settings,
wherever I am.

Paul.
-- 
Paul Howarth <paul at city-fan.org>