Forum Discussion
Tenant to Tenant Migration from Existing Hybrid Model
Our company was recently acquired, and the desire is to migrate our tenant into theirs. - we are in a Hybrid deployment (1 remaining OnPrem Exchange server** and using AzureAD Sync) - we are a r...
Don’t create duplicate AD accounts or rely on PSTs unless necessary.
The preferred path is:
- Choose the final authoritative on-premises AD.
- Preserve or migrate the existing user identities into it.
- Sync them to the target tenant using temporary addresses.
- Migrate Exchange Online and OneDrive data.
- Transfer the custom domain and apply the final UPNs and SMTP addresses.
- Retire the old sync configuration after validation.
Users can continue authenticating against local AD as long as the target tenant identities are synchronized from that AD. The last Exchange server can potentially be removed, but first validate all hybrid, relay, and recipient-management dependencies and move to the supported Exchange Management Tools-only model.