Background Cleanup interval for a mailbox store is missing

[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 https://go.microsoft.com/fwlink/?linkid=34707.]  

Topic Last Modified: 2010-07-28

The Microsoft® Exchange Best Practices Analyzer Tool reads the following registry entry to determine whether the Background Cleanup registry value is present:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIS\<ServerName>\Private-<MailboxStoreGUID>\Background Cleanup

If the Exchange Server Analyzer finds that the Background Cleanup value is missing, a warning is displayed.

If the Background Cleanup value is missing, the background cleanup process does not run and several problems may occur. These include the following:

  • Move mailbox may fail, and an event 1205 together with error code 0x4e3 may be logged.

  • Mailbox sizes and item counts that appear in Exchange System Manager or in Exchange Management Console may differ greatly from those that appear in Microsoft Outlook®. In addition, database space that is occupied by these items may not be reclaimed.

  • Unread receipts for items that were deleted without being read may not be generated under certain circumstances.

  • Cleanup of the DeliveredTo table will not occur. The DeliveredTo table is used by the Exchange store to prevent the delivery of duplicate messages. The Track Duplicates value controls the time range for which entries in the DeliveredTo table are kept. If the Background Cleanup value is present but the Track Duplicates value is missing, entries that are more than 24 hours old are purged by the background cleanup. The recommended value for Track Duplicates is 1 (decimal or hexadecimal).

We recommend that you set Background Cleanup to the default value of 60000 (decimal) or 0xEA60 (hexadecimal).

Warning

The following procedure adds the Background Cleanup value to the registry. Performing these steps can result in an increased load on the server until background cleanup has completed for all items that would typically have been cleaned up at the default interval. Therefore, we recommend that you make these changes at a time during which users will be minimally affected. Additionally, if messages for which read receipts were requested have been deleted without being read and have not been cleaned up because of this problem, unread receipts will be generated for each of those messages after you correct this problem.

Important

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 Registry Editor (Regedit.exe or Regedt32.exe).

To add the Background Cleanup Value

  1. Open Registry Editor.

  2. Locate the following subkey: HKLM\System\CurrentControlSet\Services\MSExchangeIS\<ServerName>\Private-<MailboxStoreGUID>.

  3. Create a DWORD value named Background Cleanup that has a value data of 60000 (decimal) or of 0xEA60 (hexadecimal).

  4. Close Registry Editor.

  5. To make the changes take effect, do one of the following:

    • Dismount and mount the affected information stores.

    • Restart the Microsoft Exchange Information Store service.

Before you edit the registry, and for information about how to edit the registry, see Microsoft Knowledge Base article 256986, Windows registry information for advanced users.