How can we move mailbox-enabled user accounts from one Windows 2000 domain to another domain while at the same time preserving these users' mailbox data?

The procedure for moving mailbox-enabled accounts from one domain to another is surprisingly simple. To move the accounts, just perform the following steps:

  1. Back up the user's mailbox by exporting it to a personal folder store (PST) file (this is a just-in-case step, but skip it at your peril).
  2. Use the Exchange System Manager (ESM) tool to move the mailbox to the destination Exchange 2000 Server machine.
  3. Use movetree.exe (from the Win2K Support Tools) to move the user object from Domain1 to Domain2.