Q:

Windows SMTP server suggestions?

My ancient mail server machine crapped out a few days ago.  I cobbled
together another machine from spare parts and the bone pile, which
included reformatting the existing disk and installing a fresh copy of
Windows 2000 (I've got lots of Win2000 licenses).  This will be the 
internal SMTP server for the small company I work for.
The SMTP server for receiving mail for the domain, associated POP3 server,
queuing system, and system that does some custom things including running
scripts triggered by certain mail messages is our own software and does
what we want.  What I'm looking for is a means of sending mail to external
addresses.  This software needs to contact a DNS server, do the MX lookup,
and send messages via SMTP to the various target systems.  The internal
interface to hand it mail messages can be just about anything, although
most likely that will be via SMTP also.  Free is fine, but I have no
problem paying for such software if it does what I want without problems.
However, any commercial software must have a trial period of at least 14
days because my experience is that there are a lot of gotchas and any
software needs to be proven to work.  If it works fine for 14 days I'm
happy to pay for it.
I've tried a few free programs already, but each has its problems.  One
(don't remember the name) worked great but was limited to 10 messages/day
although this was nowhere mentioned in the documentation.  That really
pissed me off, and I'd like to avoid that vendor.  I wasn't entirely happy
with the forwarding server in use before, so after 8 years or so it's time
to look around again and hopefully find something better.
To summarize, here are the requirements:

Must run on Windows 2000.
Must NOT establish a server on ports 25 or 110, or must be
configurable to avoid those ports.
Does not need security in accepting mail.  It will be behind a router
that will not expose its ports externally.
May be free or commercial.  If not free, must have at least 14 day
free evaluation period.
May use SMTP to receive mail to be forwarded, but may also require
some alternate interface, like running a executable per message.
Does not need a queuing system, POP3 server, etc.  Just needs to
forward messages to MX machines of target domains.

Any suggestions?

A:

The Internet Information Server (IIS) software that ships with Windows Server includes a basic SMTP engine that will do what you're looking for.  You can install this through the "Add/Remove Programs" section of the Control Panel.  Go into the Windows Components, then into the details for IIS and find the SMTP Service.
Once installed, it can be configured to accept connections on any IP/port combination on the server.  You can send messages through via SMTP or writing a MSG file to the pickup folder if desired.  It will handle external delivery from there.
Of course you will need to also ensure that the usual e-mail rules are followed such as having a proper reverse DNS entry on the IP you're sending from, etc.

