Follow the procedure below to re-create your mailbox, custom recipients, and distribution list files.
To re-create mailboxes, custom recipients, and DLs
Start the Microsoft Exchange Administrator program for Server B.
Recreate the same containers as you did for Server A.
From the Tools menu, choose Directory Import.
Import the Mailbox.csv file, and any other files that were previously created.
Import the Custom.csv file.
Import the file DL.csv file.
All the mailboxes, custom recipients, and DLs from Server A should now be
re-created on Server B.