Notes:

This particular client had an NT server running as their primary mail server.
It acted as a mail distribution router for several internal Exchange servers.
As well as running a proprietary Mail Server, it also ran a licensed Spam filtering
application that required an annual licensing fee for 2000 users.
The server was relatively powerful but could not handle the current mail load
of 120,000+ emails/day. First time delivery of mail would sometimes be backlogged
for more than four days.
The current mail server was also a stand-alone server with no fail-over or redundancy.