Fwd: SMTP Server

[Daniel Hood <dsmhood@gmail.com>]

Hello,

I'm building a medium-sized business network, with a few internal and
external webservers, an exchange server, a couple of IDS's and even a
network management system. Most (if not all) of these servers, require
an SMTP server in some way or form. Whether its to reset a users
password via email, or send an alert that a link has gone down.

I'm wondering, whats the best way to configure an SMTP(s) server for
this, both easily to setup and manage but also securely.

Do I set up an SMTP server on each of the servers that require one,
and then (for Anti-spam purposes) set up a MX record and PTR record to
each of them? This would require time and a lot of administration to
keep them all up.

Or do I set up one large SMTP server and authenticate via a
username/password or via ip?

Daniel