Use the procedure below to remove Server A from the organization.
To remove Server A
In the Administrator window for Server A, select Public Information Store.
From the File menu, choose Properties.
Select the Instances tab.
Remove all public folder instances from this store.
On Server A, run the Microsoft Exchange Server Setup program, and then remove the installed connectors.
Run the Microsoft Exchange Administrator program in raw mode.
From the View menu, choose All.
Select the Recipients container. In the right pane, select Microsoft Schedule+ Free/Busy Connector.
From the File menu, choose Raw Properties.
Change every occurrence from Server A to Server B to include the computer name, display name, home MDB, and home MTA. Note that you must choose Set to ensure that these changes will take effect.
In the Administrator window for Server B, select Server A, and then press the delete key. When you do so, a warning message appears stating that there is still one mailbox and gateway on Server A. This warning refers to the system attendant mailbox on Server A, which can be safely deleted.
Choose Yes. When you do so, another warning appears:
"The contents of all public folder instances on this server will be deleted. Are you sure you want to delete server 'Server A'?"
Choose Yes.
Server A will be deleted from the Microsoft Exchange Directory on Server B, and all data has been moved from Server A to Server B.