To resolve this issue, you must
verify that the Exchange Server 2007 Client Access server has the same exact
authentication settings for Outlook Web App and Exchange Control Panel . To do this, follow these steps:
- Start
the Exchange Management Console, locate and then click the Server
Configuration node,
and then select Client Access.
- View
the properties of the OWA virtual directory and note
the authentication settings.
- On the Exchange
Control Panel
tab,
verify that the authentication settings match the authentication settings that
you noted in step 2. If the authentication settings do not match, you must match the authentication settings manually.