Migrate office 365 tenant to another tenant
Traditionally, when an Exchange Online tenant needed to move a mailbox to another tenant within the same service, the mailbox had to be split from the source tenant and the data imported to the destination tenant. Such tenant-to-tenant migrations typically involve the use of third-party tools and heavy reliance on on-premises infrastructure. Microsoft has introduced a new cross-tenant mailbox migration feature that allows administrators to move mailboxes between source and destination tenants. This minimizes local system dependencies and eliminates the need to offboard and onboard mailboxes. This article describes the process of moving cross-tenant mailboxes.
The cross-tenant Exchange mailbox migration feature uses an invite and consent model to set up the Azure Active Directory (Azure AD) application used for authentication between two tenants. A cross-tenant migration movement also requires organizational relationships, migration endpoints, and other components. Prerequisites for Microsoft 365/Office 365 Cross-Tenant Migration.
Once the target administrator setup is complete, the source tenant must be prepared for Cross tenant mailbox migration using the Exchange Mailbox Migration feature.
The process of performing a cross-tenant Exchange mailbox migration is similar to an onboarding migration batch migrated from Exchange on-premises to Office 365/Microsoft 365. After setting up the necessary prerequisites, such as mailbox management roles, you can use the New-MigrationBatch cmdlet to migrate mailboxes between tenants. The target tenant admin initiates the move to retrieve mailboxes after the required tenant authentication checks in a process similar to on-premises to cloud migrations. Email users are eventually updated with the target tenant address.
The Exchange mailbox cross-tenant migration feature greatly simplifies O365 Tenant Migration, but it also has its drawbacks. Currently, this feature is initially only available in PowerShell and requires technical knowledge to trigger significant movements. Additionally, you can't perform Microsoft Teams tenant-to-tenant migrations or automatically migrate advanced archives.
