The Availability service may use lots of memory on an Exchange Server 2007-based computer

On a Microsoft Exchange Server 2007-based computer, the Availability service may use lots of memory if you are using Microsoft Office Outlook 2007 or Outlook Web Access (OWA). The corresponding W3wp.exe process will show high memory usage.

Note Multiple W3wp.exe processes may exist on the server. Therefore, check the memory usage for each W3wp.exe process.

This problem occurs because there are unnecessary caches for the MailboxSession object. These unnecessary caches use lots of memory.

To resolve this problem, install Update Rollup 3 for Exchange Server 2007. For more information about Update Rollup 3 for Exchange Server 2007, see the following Exchange Help topic: For more information about how to obtain the latest Exchange service pack or update rollup, see the following Exchange Help topic:

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

For more information about the Availability Service, visit the following Microsoft Web site: