Deletion Thread Period for a public folder store is non-default

[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]  

Topic Last Modified: 2010-07-26

The Microsoft® Exchange Best Practices Analyzer Tool reads the following registry entry to determine whether the interval for removing deleted items has been modified from the default setting:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIS\<ServerName>\Public-<PublicFolderStoreGUID>\Deletion Thread Period

If the Analyzer tool finds that the Deletion Thread Period value is present and is configured, a non-default configuration message is displayed.

When you delete a message, Exchange marks the message for deletion. Exchange also marks the message as hidden until it is permanently deleted from the Exchange store. When the information store receives a request to delete a message in a particular folder that is referenced by the Message ID, the Exchange store determines whether the message should be soft deleted or hard deleted. Soft deletion is also referred to as "logical deletion," and hard deletion is also referred to as "physical deletion." The message is permanently deleted after its deleted item retention period has elapsed.

By default, a dumpster cleanup process runs every 24 hours to determine whether it is time to hard delete an item. The dumpster cleanup process is part of the Exchange store online maintenance process. If the deleted item retention period has elapsed, the item will be hard deleted. The Deletion Thread Period registry value is used to override the default 24-hour interval and to specify a custom interval for the dumpster cleanup process.


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 revert to the default configuration

  1. Open Registry Editor.

  2. Locate the following registry subkey: HKLM\System\CurrentControlSet\Services\MSExchangeIS\<ServerName>\Public-<PublicFolderStoreGUID>.

  3. Delete the Deletion Thread Period value.

  4. Close Registry Editor.

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.

For more information about deleted item retention and recovery, see the following Knowledge Base articles: