Outlook Mobile Access Clients Cannot Access Resources and Lsass.exe Consumes 600 MB of Memory

On a heavily loaded Microsoft Exchange Server 2003 front-end server, when clients who log on by using Microsoft Outlook Mobile Access try to access a resource, they may receive error messages that are similar to the following message: Additionally, when you use the Windows Task Manager to view the processes that are running on the Exchange Server 2003 computer, you notice that the Lsass.exe process has a very high memory usage. Sometimes Lsass.exe memory usage is more than 600 megabytes (MB).

This issue may occur if Exchange 2003 is installed on computer that is running Microsoft Windows 2000 Server Service Pack 3 (SP3) or earlier.

You may experience this issue during prolonged stress testing of Exchange 2003.

To resolve this issue, install the hotfix update that is described in the following Microsoft Knowledge Base (KB) article:

To work around this problem, restart the Exchange 2000 computer. You can also use the /3GB switch in the Boot.ini file to add additional virtual address space. For additional information about how to optimize memory usage on an Exchange server, click the following article numbers to view the articles in the Microsoft Knowledge Base: