I am trying to configure my new T-Mobile Wing's Outlook to sync via the Internet connection with our Exchange server. The Exchange server is set to allow all OMA and OWA access. Per the T-Mobile instructions I pointed the email synce to the public IP address of our Outlook Web Access server by both IP address and then tried URL address. Both times it could not find the Exchange server. This makes me think that there is something more I need to open up through the firewall, but I don't know what it is. Any help?

I would suggest looking at the logs on your firewall to determine if a port is blocked. It should be obvious if you filter by the destination address of your OWA server.