Win 2003 SP1 & Exchange 2003
If you are looking to roll out Windows Server 2003 SP1 on your Exchange servers and you are doing clustering on back-end servers, we have a hotfix (Q841561) that you will need to install.“This problem is caused by some of the security enhancements that are included with Windows Server 2003 SP1.
In this scenario, when a user tries to access a mailbox by using Outlook Web Access, HTTP requests into the clustering API by impersonating the logged-on user. However, there have been security changes in Windows Server 2003 SP1. The security restrictions for the APIs that perform remote registry access have been changed. Therefore, the logon attempt is not successful.” (more)








