This hotfix will not resolve this problem if the following conditions are true:
- You have multiple Microsoft Exchange Server accounts that use different user credentials.
- You set the UseWindowsUserCredentials value to 1 in the registry.
For example, you log on to Windows as
Fourthcoffee\User1. However, you start Outlook with a profile for the mailbox of
Fourthcoffee\User2.
In this scenario, Outlook connects to Active Directory by first doing a referral remote procedure call (RPC) against the Exchange Server. This is followed by a second RPC to Active Directory that the referral provides. Neither of these RPCs requires any information about the mailbox account. In this case, the mailbox account is
Fourthcoffee\User2.
By default, Outlook always tries the credentials that you use to log on to the computer first, in this case
Fourthcoffee\User1. Therefore, this connection is considered successful. That is, the computer credentials for
Fourthcoffee\User1. Then, Outlook tries to connect to the mailbox for
Fourthcoffee\user2. Because the credentials for
Fourthcoffee\User1 were successfully used during the Active Directory referral process, Outlook tries these same credentials to log on to the mailbox for
Fourthcoffee\User2. Because
Fourthcoffee\User1 does not have permissions to the mailbox for
Fourthcoffee\User2, the mailbox logon fails. Access is denied. Because
UseWindowsUserCredentials is set to 1 in this example, Outlook uses only the desktop credentials and suppresses the credentials prompt. Therefore, it silently fails repeatedly.