AboutFree templates
Decision helper

Which Exchange migration method should you use?

Your Exchange version, mailbox count, need for coexistence and directory sync decide the method. Answer the questions to get a recommendation that matches Microsoft's migration path guidance.

4 questionsTakes about a minuteBased on official guidance
Which Exchange version is your oldest mailbox server?

1. Which Exchange version is your oldest mailbox server?

Run Get-ExchangeServer | Format-Table Name,AdminDisplayVersion in the Exchange Management Shell.

How many mailboxes are moving?

2. How many mailboxes are moving?

Count user, shared and resource mailboxes. Microsoft suggests cutover for fewer than 150 and caps it at 2,000.

How long will on-premises and cloud mailboxes need to work side by side?

3. How long will on-premises and cloud mailboxes need to work side by side?

Coexistence means shared free/busy, one global address list and secure mail flow between the two systems while users move.

Will on-premises Active Directory stay the source of user accounts after the move?

4. Will on-premises Active Directory stay the source of user accounts after the move?

If you keep directory sync, recipient attributes stay managed on-premises, so Exchange (or its management tools) stays for administration.

This helper applies the rules in our How to migrate from Exchange Server to Exchange Online and the vendor documentation below. Your situation may have factors it does not ask about, so read the playbook's "Choose your approach" section before you commit.

Sources

Microsoft Learn: Decide on a migration pathMicrosoft Learn: Cutover migration to Exchange OnlineMicrosoft Learn: What you need to know about a staged migrationMicrosoft Learn: Use Minimal Hybrid to quickly migrate Exchange mailboxesMicrosoft Learn: Hybrid Configuration wizard optionsMicrosoft Learn: Hybrid deployment prerequisitesMicrosoft Learn: Deploy dedicated Exchange hybrid appMicrosoft Learn: Move mailboxes between on-premises and Exchange OnlineMicrosoft Learn: Remove the last Exchange server in a hybrid deployment