Outlook 2003 / Exchange Server won't connect.

I installed Win7 (at home) and when I try to configure Outlook 2003 to
connect to the exchange server that our company uses. It cannot get access to this
server. It says outlook must be online to access the exchange server.
All other internet access works perfectly. I've checked and rechecked all the settings. They are correct. It worked fine on VISTA. I did a Windows 7 Ultimate upgrade. Continues to work fine on my XP Pro station. Seems like something is blocking it from going out over the internet.

I did try to turn off the Firewall but this did not help.

Any suggestions?