Disconnected Mailboxes Reconnect After the Owner Is Removed from Active Directory

After you delete a mailbox, it is reconnected, even if you removed the owner from Active Directory directory service. The mailbox is not deleted.

In Microsoft Exchange 2000 Server, if you delete a mailbox, it is disconnected for a default period of 30 days (30 days is the mailbox retention period), and you can reconnect it at any point during that time. When you delete a mailbox, it is not deleted from the information store database immediately. Instead, the mailbox is flagged for deletion. At the end of the mailbox retention period, the mailbox is permanently deleted from the database.

However, a system-generated message (such as a "quota full" warning message) that occurs before the mailbox is permanently deleted, can sometimes reactivate and reconnect a disconnected mailbox (it resets the ptagDateDiscoveredAbsentInDS flag) even if you removed the owner from Active Directory. This prevents the mailbox from being deleted.

NOTE: You can configure the deleted mailbox retention period at the mailbox store object level.

To work around this issue, run the cleanup agent, which disconnects the mailbox and marks it for deletion, and then use Exchange System Manager to manually clear the mailbox.

To resolve this issue, follow these steps:

1. Start Active Directory Users and Computers snap-in, right-click the user, click Exchange Tasks, and then click Delete Mailbox.
2. Click Next, and then click Next again, to confirm the deletion. Click Finish.
3. Start Exchange System Manager, right-click the Mailboxes object under the mailbox store, and then click Run Cleanup Agent. Note that the mailbox that is destined for deletion appears in Exchange System Manager with a red X icon.
4. Right-click the mailbox, and then click Purge to permanently delete the mailbox. Click Yes to confirm the deletion.

Microsoft has confirmed that this is a problem in Microsoft Exchange 2000 Server.