Forum Discussion
Groups: Tenant to tenant migration
Groups use special forms of mailboxes that not all migration tools even reveal let alone access... That is my warning.
Just as an example, try using the Get-Mailbox cmdlet to list group mailboxes. They don't exist. You have to use Get-UnifiedGroup. But you can feed a group mailbox id into Get-MailboxStatistics... So it's inconsistent, hence the warning.
Treat each Microsoft 365 Group as a bundle of workloads, not a single migration object. Inventory owners, activity, retention requirements, guests, permissions, Planner plans, notebooks, connectors, apps, flows, and tabs, then archive inactive groups and pilot the complete process with representative groups before cutover. Microsoft’s current orchestrator supports Exchange mailboxes, OneDrive, Teams chats, and Teams meetings, while SharePoint uses its separate cross tenant migration path, so confirm Planner, OneNote, connectors, and other integrations against your chosen tool and plan to recreate anything unsupported.
For OneNote, do not copy notebook folders as ordinary files because notebooks use their own synchronization mechanism. Migrate through a tool that explicitly supports notebooks, or recreate the notebook in the target and move sections through OneNote, then validate links, permissions, Planner assignments, connector credentials, mail flow, and target membership before making the source group read only or deleting it.