Outlook Anywhere clients require hotfix to support load balanced deployments

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at http://go.microsoft.com/fwlink/?linkid=34707.]  

Topic Last Modified: 2010-06-28

The Microsoft Exchange Server Best Practices Analyzer Tool determines whether the update that is described in Microsoft Knowledge Base article 977592 is installed on the computer. If the update is not installed, you receive the following message:

This computer requires the update described in Microsoft Knowledge Base article KB977592 (http://support.microsoft.com/?kbid=977592). Without this update, the Outlook Anywhere feature may work unreliably.

If you receive this error message, you must install the update that is described in the following Microsoft Knowledge Base article:

977592, RPC over HTTP clients cannot connect to the Windows Server 2008 RPC over HTTP servers that have RPC load balancing enabled

Microsoft Office Outlook uses the Outlook Anywhere feature to connect to Microsoft Exchange Server over the Internet. Outlook Anywhere is dependent on a Windows OS component that is named RpcProxy. There was a problem in RpcProxy that was fixed in Windows Server 2008 R2 and that was also fixed by an update for Windows Server 2008.