Exchange 2010 installation is coexisting with exchange 2003 in my environment.
Outlook web app works fine and I can move mailboxes to 2010 no problem.
If I try to setup first time the outlook profile for any exchange 2010 mailbox user, when I click on the 'check name' in outlook 2003, even though I have entered the name of the Exchange CAS server and enabled the checkbox in outlook for encrypting exchange connections,I receive the following error "The connection to Microsoft exchange server is unavailable. Outlook must be online or connected to complete this action"
If instead of the exchange 2010 cas name, I use the exchange 2003 server name, and I click 'check name' in outlook, the username resolves correctly and the exchange server name is automatically changed to the exchange 2010 server name. However when outlook opens, I receive error:
"Unable to open your default folders. You must connect to your exchange server computer with the current profile before you can sync your folders with your offline folder file"