How to troubleshoot mail relay issues in Exchange Server 2003 and in Exchange 2000 Server:
http://support.microsoft.com/?kbid=895853
Description of a hotfix that enables Exchange Server 2003 to log an event when a user deletes a public folder:
http://support.microsoft.com/?kbid=891968
After you run the Security Configuration Wizard in Windows Server 2003 SP1, Outlook users may not be able to connect to their accounts:
http://support.microsoft.com/?kbid=896742
Windows Update stops responding if you click Install to download and install updates for Windows XP or Windows 2000:
http://support.microsoft.com/?kbid=896227
You cannot download updates when you access the Windows Update Web site from a Windows XP-based computer that is behind a firewall or a proxy server:
http://support.microsoft.com/?kbid=896226