You receive an error message informing you that one or more users still have a mailbox on an Exchange server that you are trying to uninstall.
When attempting to decommission an Exchange server by running the setup program to remove the installation, you receive the following error:
One or more users currently use this mailbox store. These users must be moved to a different mailbox store or be mail disabled before deleting this store.
ID no: c1034a7f
Exchange System Manager
This is despite the fact that you think you have already removed all the mailboxes off of this server. You follow the instructions in Microsoft Knowledgebase article 279202 but this makes no difference.
It is likely that there are still some objects with Active Directory that have Exchange attributes configured. These need to be removed before the Exchange server can be uninstalled.
To find the objects with Exchange attributes, use the Active Directory Users & Computers snap-in.
- Run Active Directory Users & Computers.
- Right-click your domain at the top of the tree and click Find.
- Click the Advanced tab and then choose User from the Field button.
- From the list of attributes displayed, choose Exchange Home Server.
- Set the Condition field to Ends With and then type the name of your Exchange server into the Value field. Click Add to add this value.
- Click the Find Now button which should now display the problematic objects.
The Exchange attributes can now be removed from these objects and the uninstall process attempted again.