I’m currently gathering information for an upcoming Microsoft 365 migration project following Mergers & Acquisitions. One requirement that’s receiving a lot of attention is how to Migrate Shared Mailboxes between Office 365 Tenants without affecting business operations or requiring excessive manual work.
Our shared mailboxes are actively used by Finance, HR, Sales, and Customer Support teams, so maintaining mailbox structure, delegated access, and existing data is extremely important. Since employees will continue working throughout the migration, we’d also prefer a solution that supports incremental synchronization instead of copying the same data repeatedly.
After reading Microsoft’s documentation, it seems the native approach works but requires considerable planning, scripting, user mapping, and verification. For organizations with hundreds of users, that can quickly become difficult to manage.
Because of that, I’ve been looking at several DRS Softech Office 365 Tenant to Tenant Migration Tool options that offer centralized management for Exchange Online, SharePoint Online, and OneDrive migrations. One solution I found was the DRS Softech Office 365 Tenant to Tenant Migration Tool. Based on its published features, it supports Microsoft Graph API connectivity, Modern Authentication, flexible mailbox mapping, migration filters, real-time monitoring, and detailed reporting, which all sound useful for enterprise environments.
We’re still in the planning phase, so I’m interested in hearing how other administrators approached their migration projects. It’s always helpful to learn from real-world experiences before starting a large-scale tenant migration, especially when shared mailboxes are involved.