Topic Last Modified: 2007-01-08

The Microsoft® Exchange Server Analyzer Tool reads the following registry entry to determine whether the default maximum number of folder views that can be opened per MAPI session has been changed:


If the Exchange Server Analyzer finds the objtFolderView registry value present and configured with any value other than 500, a non-default configuration message is displayed.

When manually added and configured, the objtFolderView registry value determines the maximum number of folder views that can be opened per MAPI client. By default, Exchange Server 2003 and Exchange Server 2007 limit the number of open folder views to 500. When a MAPI client tries to open more than 500 folder views, the following event is logged in the application event log on the Exchange Server computer that contains the client's mailbox:

Event Type: Error

Event Source: MSExchangeIS

Event Category: General

Description: Closing Mapi session "/o= OrganizationName /ou= AdministrativeGroupName /cn=Recipients/cn= UserName " because it were greater than the maximum of 500 objects of type "objtFolderView".

The objtFolderView registry value represents a configuration opportunity that provides an administrator with a greater level of control over the Exchange Server resources used by MAPI clients.

This article contains information about how to edit the registry. Before you edit the registry, make sure that you understand how to restore the registry if a problem occurs. For information about how to restore the registry, view the "Restore the Registry" Help topic in Regedit.exe or Regedt32.exe.

To revert to the default configuration

  1. Open a registry editor, such as Regedit.exe or Regedt32.exe.

  2. Navigate to:


  3. Delete the objtFolderView registry value.

  4. Close the registry editor and restart the Microsoft Exchange Information Store service for the change to take effect.

  5. Alternatively, if you want to use the objtFolderView registry value, instead of deleting it, keep it set to its existing value, or adjust it as needed.

Before you edit the registry, and for information about how to edit the registry, see the Microsoft Knowledge Base article 256986, "Description of the Microsoft Windows Registry" (

For more information, see Microsoft Knowledge Base article 830829, "Your Exchange Server 2003 computer may stop responding after a MAPI client opens more than the default value of certain server objects" (