Exchange Cross Tenant Data Migration Add On Now Available
Microsoft announced this week that its cross-tenant data migration add-on capability for Exchange Online users or "hybrid" Exchange" users is now released at the "general availability" commercial-release stage.
The cross-tenant data migration capability is commercially released for so-called Exchange "WW tenants" when moving mailboxes over to "other WW tenants." The capability is still at the preview stage for "GCC High tenants" and "DoD tenants."
Exactly what the WW term means may be obvious ("worldwide" maybe), but I couldn't locate it in Microsoft's public "tenant definition" documentation. The other tenant types, GCC High and DoD, are tenant offerings for government agencies.
Microsoft's announcement also doesn't explain that the cross-tenant data migration capability is an add-on offering to organizations with certain licenses (from F1 to E5/A5), with a one-time cost. That detail is stated in Microsoft's "Cross-Tenant Mailbox Migration" documentation, as follows:
Cross Tenant User Data Migration is available as an add-on to the following Microsoft 365 subscription plans for Enterprise Agreement customers. User licenses are per migration (onetime fee). Please contact your Microsoft account team for details.
The supported licenses can be found listed in Microsoft's documentation.
Organizations need to configure the target destination first to carry out an Exchange cross-tenant data migration. The migration capability will just move visible mailbox items, namely "email, contacts, calendar, tasks and notes," to the target destination.
The migration capability will automatically delete the source mailbox after the move completes. "This means that after the migration, under no circumstances, is the source mailbox available, discoverable, or accessible in the source tenant," the documentation explained, in a "Note."
Things like e-discovery won't work at the source after a data migration. Mailboxes with legal holds won't get moved.
IT pros have lots of steps to follow when using the Exchange cross-tenant data migration capability, but it's apparently easier than prior methods that required them to "export or offboard the mailbox to on-premises and then import or onboard the mailbox to a new tenant," per Microsoft's characterization.
Microsoft advises not exceeding "2,000 mailboxes per batch" for these cross-tenant data moves.
Microsoft also offers a cross-tenant data migration capability for OneDrive storage, as described in this document. It supports up to 4,000 OneDrive accounts per move.
This migration capability currently doesn't support cross-tenant migrations of Microsoft 365 Groups, nor are Teams chat folders moved. Microsoft also noted that migrated mailboxes will lose connections to Teams in the source tenant, which was described as a "known issue."
Organizations will need Organization Administrator role permissions to complete the setup tasks need for these cross-tenant data migrations. The actual migration execution, though, can be delegated to a lower permissioned role.
Microsoft's documentation included a "Tip" indicating that Microsoft is working on a capability to automate the attributes settings that are needed at the target destination. This tool, called "Cross-Tenant Identity Mapping," is currently at the private preview stage.
Kurt Mackie is senior news producer for 1105 Media's Converge360 group.