First let’s understand when it happens. After move of mailboxes between 2 exchange stores some times duplicate mailboxes remain .. When you try to delete them you receive error “The operation cannot be performed because this mailbox was already reconnected to an existing user.” ID no. c1034ad6.
So to delete the annoying mailbox go to active directory users and computers , select the user that holds both mailboxes run “exchange tasks” and select “remove exchange attributes” then go to duplicate mailbox with red X and reconnect the mailbox. When duplicate mailbox is connected you can delete him. After successful delete purge the red X mailbox and reconnect the old mailbox back..
I also found Microsoft Article related to this issue , seems that the problem is related to Exchange 2003 sp2 installation. You need to obtain hotfix in order to resolve the problem. http://support.microsoft.com/kb/940012
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just a comment: try moving the mailbox back to the server where the disconnected mailbox is located. The procedure will fail, but the disconnected mailbox is deleted.
/Chris
Thanks Chris! That worked so perfectly! Way easier than anything else I have come across!
Remove the orphaned mailbox by using Exchange maintenance
Start Exchange System Manager.
Locate and then click the mailbox store that you want. For example, to locate the Mailbox Store (My_Server) store, follow these steps:
Expand Administrative Groups, expand First Administrative Group, expand Servers, and then expand My_Server.
Expand First Storage Group, and then click Mailbox Store (My_Server).
On the Action menu, click Properties, and then click the Limits tab.
Under Deletion settings, type a number that is less than the age of the orphaned mailbox in the Keep deleted mailboxes for (days) box. For a mailbox that is newly orphaned, type 0 (zero).
Configure the maintenance schedule. To do this, follow these steps:
Click the Database tab.
In the Maintenance interval box, click Use custom schedule, and then click Customize.
In the list of days, click the current day so that the row for that day is highlighted. This schedules the maintenance for all day.
Note The scheduling of maintenance for all day can be set or removed. To do this, click a day in the list of days.
Click OK.
Exit Exchange System Manager.
Allow for online maintenance to finish. This may take several hours. You will see event ID 1221 logged in the Application log when online maintenance is finished.
In Exchange System Manager, use the Run Cleanup Agent on the Mailboxes folder that contains the orphaned mailbox.
Move mailbox back to original store. Process will Error and Fail. Refresh ESM and you will find that the duplicate mailbox has been deleted.
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Thanks Chris. Attempting to move the mailboxes back to the original server failed, but removed the problem duplicates. Worked like a charm.
Chris above has the easiest method to resolve this by far. in ESM, rightclick the “good” mailbox and move it (exchange task) to the location of the “bad” mailbox. the operation will fail, and the bad box will be gone.