In a Microsoft Exchange Server 2010 environment, you use Microsoft Office Outlook Web App to log on to Exchange Control Panel. When you select Options, a logon prompt is presented again for authentication. However, you should have a single sign-on experience and the prompt should not appear.
This issue occurs because the Outlook Web App virtual directories and Exchange Control Panel virtual directories do not have the same authentication settings.
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.