Exchange 5.5 connection Problem

[Greg]

I am having a liittle problem that I can's seem to figure
out why it is happening. I just loaded Office 2003 Pro
and when I go into Outlook and setup a connection to the
exchange server the settings get changed. I tried the ip
address of the server, the internal server name, and the
external server name but for some reason it sits and
spins the wheels and then changes the server to
www.mydomain.com<-----being our actual domain name. I
hav done this on 10 other computers with out a hitch
until now. I am at a lost on how to fix this problem.

Any help would be great!

Thanks,
Greg