I won't know how you use the ms exchange server, but mostly you will find a .ini file where you will setup the SMTP. It's easy only two or three lines.
On some ms exchange server you should install SMTP first.
I did not have a look for software who will do it automatically without the searching for the .ini file, but I guess somewhere you will find it.
Take this:
--> Exchange Systemmanager --> Details / Characteristics (near Server Protocol)--> Access (Action) --> Relay -->
tick: only Computer at list --> be carefull that the Computer list is empty.

simple SMTP Test with any second Computer and telnet:

C:\>telnet mailin.msfairs.net 25_

use your own Server address instead of mailin.msfairs.net
On some Vista and XP PC's telnet is deactivated use apple or other.