Topic Last Modified: 2007-01-17

The Microsoft® Exchange Server Analyzer Tool reads the following registry entry to determine if the number of days that the SMTP service routing engine bypasses the new public folder store has been manually set:


If the Exchange Server Analyzer finds IgnorePFTimeLimit to be present and configured, a non-default configuration message is displayed.

When a new public folder store is brought online, you may notice in the Queue Viewer that the local delivery queue is growing. If the public folder hierarchy is large, the messages in the local queue continue to grow and may take additional time to be delivered. In some cases, the messages may not be delivered.

When the new server is introduced, its distinguished name is added to the msExchOwningPFTreeBL attribute of the administrative group's Folder Hierarchies Public Folder object in the Active Directory® directory service. When the categorizer for the server that receives messages bound for public folders reads the msExchOwningPFTreeBL attribute, it should first select the local public folder store, if it exists. For load balancing, it then selects the public folder stores in the order that they are listed. Because the new server is listed first, the messages are routed to it, where they are added to the new server's local delivery queue. If a public folder store has not received a copy of the hierarchy, the server cannot route the messages to a store that owns a copy of the destination folder.

You can avoid this issue by adding the IgnorePFTimeLimit value to the registry of the new public folder server. This will specify the number of days that the routing engine bypasses the new public folder store.

This article contains information about editing the registry. Before you edit the registry, make sure 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: HKLM\System\CurrentControlSet\Services\SMTPSvc\Parameters

  3. In the right-hand pane, delete IgnorePFTimeLimit.

  4. Close the registry editor, and then restart the IIS Admin service for the change to take effect.

For more information about the issue and the IgnorePFTimeLimit registry value described in this article, see Microsoft Knowledge Base article 328870, "XADM: Public Folder Routing is Enabled Before the Hierarchy is Replicated" (

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