To resolve this problem, make sure that the mailbox store
		  that contains the System Attendant mailbox is mounted on the recovery server.
		  Typically, the System Attendant mailbox is homed on the first mailbox store
		  that is named 
Mailbox Store
		  (Server_Name).
Method 1 : Mount the mailbox store that contains the System Attendant mailbox
Note By default, the System Attendant mailbox is created in the first
		  mailbox store in the first storage group on the first Exchange server. 
		  
- Click Start, point to
				Programs, point to Microsoft Exchange, and
				then click System Manager.
 - If Administrative Groups are not enabled, go to step 3. If
				Administrative Groups are enabled, expand the Administrative
				Groups container, and then expand the first
				Your_Administrative_Group
				container.
 - Expand the Servers container.
 - Expand the first Your_Server
				object.
 - Expand the First Storage Group
				object.
 - Right-click the Mailbox Store
				(Server_Name) store object, and then click
				Mount Store.
 - Click OK.
 - Expand the Mailbox Store
				(Server_Name) object, and then click
				Mailboxes.
 - In the right pane, verify that the System
				Attendant mailbox exists. If you do not find the System Attendant
				mailbox, right-click the Mailboxes container, and then click
				Run Clean-up Agent. The System Attendant
				mailbox will appear and will be connected.
 - Exit Exchange System Manager.
 - Run ExMerge.
 
Method 2: Create a  Recovery Storage Group (RSG) and restore a production database
- Make sure that the System Attendant Mailbox is present on
				the server where the Recovery
				Storage Group is created.
 - The Mailbox Store that
				holds the System Attendant
				Mailbox should also be mounted.
 - Before you
				create a Recovery Storage
				Group and restore
				any production mailbox store to the RSG, we recommended that you make sure that
				you already have a Mailbox Store on this server that has the System Attendant
				Mailbox.
 
Note On Exchange 2003, you can have one usual  Mailbox store which has
		  the System Attendant mailbox and one RSG store. You cannot create a Mailbox
		  Store after the RSG store was created. Make sure that the usual  Mailbox
		  store that has the System Attendant mailbox is created first and then create
		  the RSG and restore the production database to it.
		  
- If you already created a Recovery
				Storage Group on an Exchange 2003 server and restore a
				production database to it, you will need to dismount and delete this RSG and
				create a normal Mailbox Store first.
 - You can run the Cleanup agent to force the System Attendant
				mailbox generation.
 - As soon as the System Attendant mailbox is generated, you can
				create a
				new RSG and connect to the same .edb and .stm restore
				database.
 - Connect the RSG to the related Production Mailbox Store and
				then mount it.
 - You should be able to use ExMerge successfully
				now.