Kurt Shintaku's Blog

On a Windows AD-based network using Outlook connected into Exchange, most people expect that they won’t need to enter any credentials.  After all, your AD credentials used upon login should be enough to provide pass-through authentication.

However I’ve noticed that some folks have encountered a situation where once they start Outlook, it indeed requests (via a pop-up dialog box) that the user retype their AD username and password… much to the bother & annoyance of the user.

The issue may be that you have multiple cached credential entries for Outlook stored within Windows – which take precedence over Windows Authentication – and Outlook doesn’t know which to use.  Here’s how to delete them and get back to using seamless Windows Pass-through authentication for connecting into Exchange via Outlook:

Delete the personal credentials
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If you are running Windows 7, remove the user’s stored credentials in Windows Credential Manager. To do this, follow these steps:

1. Click Start, click Control Panel, and then click Credential Manager.
2. Locate the set of credentials that is used to connect to Exchange. The credentials should be shown as MS.Outlook: username@…
3. Expand the set of credentials, and then select Remove from Vault.

Now when you start Outlook it’ll use your cached corporate domain login without prompting.