I'm still not sure that this is an Outlook issue.

Breakdown:
1. Outside user's Outlook 2003 client cannot connect to the Exchange
server over the internet. Status icon in the lower Right corner shows
"Disconnected" not "Offline"
2. OWA in Internet Explorer 6 connects to the default http landing
page of the server but when it redirects to the https page I get error
about Server Unavailable.
3. When connected via VPN, both methods of connecting to email work
without problem.
4. A second computer in this same users network can connect to OWA
without any problems, this computer is not set up for VPN and does not
belong to the domain.
5. All other outside users (30+ of them) are not having any issues.
6. This problem started 1 week ago.
7. The address for the mail server resolves correctly during a PING
test on the afflicted computer.
8. Outlook Profile has been completely rebuilt.

How can I get Outlook to connect to Exchange over the internet without
having to log onto the VPN again?