Topic Last Modified: 2005-11-17

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

The msExchMailboxRetentionPeriod attribute indicates the number of days to retain deleted mailboxes before deleting them. You can select a number from 0 to 24,855 when specifying the number of days to retain a deleted mailbox. The default setting for deleted mailbox retention is 30 days. If the mailbox retention period is set to 0, deleted mailboxes are permanently removed from the server immediately. Unless disk space is an issue, it is recommended that you do not disable the deleted mailbox retention feature.

To configure deleted mailbox retention

  1. Open Exchange System Manager.

  2. Expand Administrative Groups, expand your administrative group, expand Servers, and then expand your storage group. If the Administrative Groups node is not displayed in Exchange System Manager, expand Servers, and then expand your storage group.

  3. Right-click the mailbox store you want to configure, and then select Properties.

  4. On the Limits tab, enter a mailbox retention period in the Keep deleted mailboxes for (days) field.

  5. Click OK to save the changes.

Note:
You may be able to recover a mailbox if its mailbox retention period has not expired and the associated user object is not deleted.

For more information about recovering a deleted mailbox, see the following Microsoft Knowledge Base articles: