email migration without a source server
We're moving from a 3rd-party external email service to an in-house Zimbra installation. The Zimbra server is set up with a MX record for a test domain, and our production email domain is still pointed at the external server.
Test email accounts are performing well, and I'm ready to move the users, but need some advice on my plan.
Users are accessing mail via POP session using an Outlook client, so I have only local pst files to use as source.
Here's what I had planned:
1. Create all users in the test domain
2. Import each user's pst files (multiple PSTs per user) into this test domain with the CLI tool.
3. Test send/receive for each user in test domain.
4. Create the production domain, and migrate the users from the test domain to it.
5. Modify the MX record for the production domain to point to the new Zimbra server.
Please let me know whether this plan is adequate, or whether there's a better method. Thanks in advance.