When Migrating Exchange, normally the Outlook client software needs to re-target itself to the new Exchange server. Outlook will check in with the old Exchange server and will learn that it needs to connect to a different Exchange. If the old Exchange server is turned off, the service are stopped, or it has been uninstalled, you will be left with a Outlook client that will not open.
Normally just turning on the old Exchange server, then starting the Outlook client will be sufficient to remedy this, however if the old Exchange server has been uninstalled then the Outlook client will be trapped. This is especially unnerving on a terminal server, where mlcfg.cpl will probably be restricted from executing.
A work around that I have found is to start outlook.exe with the command line switch, /profiles. This will launch a dialog window where you can create a new mail profile, configure it for the new Exchange server and set it to be the default profile.
