You can merge separate servers into one server by performing an export to a file, editing the files, and then importing the files to the new server:
- On each of the servers from which you want to export files:
- On the Tools menu, click Directory Export.
- Complete the appropriate information in the Directory Export dialog box to specify the Exchange Server recipients' containers and servers that you want to export from.
- Under Export objects, click to select the Mailbox and the Custom recipients check boxes, and then click Export.
- Follow the on-screen instructions to export the file to a specific drive and folder.
- Open the exported files in Microsoft Excel to edit data under the Home-Server, OBJ Container, and Addressing field (X400 addressing) columns as needed.
- For each of the exported files, in Exchange Server, on the Tools menu, click Directory Import to import the file into the new Exchange server.
- Use Exmerge against the Exchange server and export mail messages to a .pst file.
- Send a message to all Exchange Server users, asking each user to create a mailbox, and then use Exmerge against the new server to import the newly created .pst files.