Topic Last Modified: 2005-11-17

The Microsoft® Exchange Server Analyzer Tool queries the Active Directory® directory service to determine the value for the garbageCollPeriod attribute of each public folder store. If the Exchange Server Analyzer finds the garbageCollPeriod attribute set to 0 for any public folder store, a best practice recommendation message is displayed.

Garbage collection is an internal Exchange housekeeping process that frees space within the public folder store database. By default, deleted items are stored in the public folder store database for a certain number of days before they are permanently deleted by Exchange. You can set the length of the deleted item retention period by either using the public folder store defaults, or by selecting the number of days that a deleted item is kept before it is permanently deleted.

You can select a number from 0 to 24,855 when specifying the number of days to retain a deleted item. It is recommended that you configure this setting to 7 days. If the deleted item retention period is set to 0, the deleted items are permanently removed from the server immediately. Unless disk space is an issue, it is recommended that you do not disable the deleted item retention feature.

To configure deleted items retention in Exchange System Manager

  1. Open Exchange System Manager.

  2. Expand the Administrative Group or Servers, click Servers, and then click Public Folder Store.

  3. Right-click the public folder store, and then click Properties.

  4. On the Limits tab, set the deleted items retention period by doing the following:

    • To set a retention period for deleted items, click Keep deleted items for (days), and then type a value.

    • To preserve items until backup, click Do not permanently delete items until the store has been backed up.

For more information about setting storage limits for public folders, see the Microsoft Knowledge Base article 319439, "HOW TO: Configure Storage Limits on Public Folders in Exchange 2000" (