Microsoft 365 Cross-Tenant Mailbox Migration (native)
Microsoft
Included
Near-zero - continuous sync, minutes to cut over
Agentless
Enterprise estates
Exchange
What it is good at
Moves the mailbox itself rather than copying items, so nothing is re-ingested and no per-mailbox fee is paid. Best fidelity available for tenant-to-tenant.
Where it falls down
PowerShell only - no GUI, no scheduling, no progress dashboard. Does not move OneDrive, SharePoint, Teams chat or Power Platform. Target addresses must be pre-staged as MailUsers.
Capabilities
- Delta / incremental passes
- Coexistence during migration
- Programme reporting / audit trail
Cost and licensing
- Cost category
- Included — No extra charge if you already hold the platform licence.
- Indicative price
- No per-mailbox fee; both tenants need appropriate M365 licences
- Licence model
- Native Exchange Online feature. No migration SKU; source and target users must hold Exchange Online / Microsoft 365 licences.
- How to license it
- Configure a cross-tenant migration Entra application and mailbox migration endpoint with the ExchangeOnlineManagement PowerShell module. Nothing to buy. Note Microsoft has signalled licence requirements around some cross-tenant capabilities - confirm current terms for your tenants.
- Lifecycle
- Current
- Vendor page
- https://learn.microsoft.com/microsoft-365/enterprise/cross-tenant-mailbox-migration
Pricing and licensing last reviewed 2026-09-18. Indicative only - confirm with the vendor.
Supported sources
- Any platform
Supported targets
- Any platform
Scenarios it covers
- Microsoft 365 tenant to tenant
- Merger - mail, files and Teams together
- Divestiture - carve mailboxes out to a new tenant