Knowledgebase/Migration Planning/Exchange Server 2003

How do I increase the MAPI named property limits?

MigrationWiz Support
posted this on March 16, 2011 21:32

Some Exchange servers that have been in commission for years may hit MAPI named property limits. These limits are reached when we attempt to retrieve more properties than the server is configured for. You will know if your server reaches these limits as an event similar to the following is logged:

Event Type: Error
Event Source: MSExchangeIS
Event Category: General
Event ID: 9667
Date: 6/11/2010
Time: 4:56:13 PM
User: N/A
Failed to create a new named property for database "First Storage Group\Mailbox Store (SERVERNAME)" because the number of named properties reached the quota limit (8192).
User attempting to create the named property: "SYSTEM"
Named property GUID: 00062002-0000-0000-c000-000000000046
Named property name/id: "33377"
For more information, click

To increase the number of MAPI named properties:

  1. Start the Registry Editor on the mailbox server
  2. Locate the registry key HKLM\SYSTEM\CurrentControlSet\Services\MSExchangeIS\<ServerName>\<Private-GUID>
  3. Set the following DWORD values or create new values if they do not exist
    • NonMAPI Named Props Quota == 00007fff
    • Named Props Quota == 00007fff


You may either wait approximately 30 minutes for these values to take effect automatically or reboot the server to take effect immediately.

These instructions have also been documented on the Microsoft website.