Google Workspace to Microsoft 365 migration: what to expect

Teams usually move off Google Workspace for a reason outside email itself: clients and partners standardizing on Microsoft 365, a need for Entra ID and Intune to manage devices properly, or Microsoft tools the business has already standardized on elsewhere. The migration itself is mechanical once you know the sequence; the risk is almost entirely in the cutover, not the data move.

What actually moves

Gmail becomes Exchange Online mailboxes, Google Drive files become OneDrive and SharePoint content, and Google Calendar and Contacts map to their Outlook equivalents. Shared drives need a decision up front: a straight folder-for-folder copy into SharePoint works for most teams, but it's worth re-mapping permissions rather than copying them as-is, since Google's sharing model and SharePoint's don't match one to one.

The real risk is mail routing, not the data copy

Copying mailbox data rarely breaks anything. What causes an outage is the DNS cutover: MX records pointing mail at the wrong system for the window between turning Google off and Microsoft 365 fully live. The fix is sequencing, not luck: migrate mailbox data first while both systems run in parallel, then cut MX records over in a planned, low-traffic window, with the old system still reachable as a fallback for a few days.

Migration is also a chance to fix the security baseline

A lift-and-shift migration that copies Google Workspace's permission sprawl into Microsoft 365 wastes the one moment you have to start clean. Setting up Entra ID conditional access and MFA enforcement during the migration, rather than after, means users never experience the "secure it later" gap where most real incidents start.

A short checklist

• Has shared drive and folder permissions been re-mapped, not just copied as-is?
• Is there a parallel-run window before MX records cut over, not a single hard switch?
• Is MFA and conditional access configured as part of the migration, not a follow-up task?
• Is there a defined rollback window where the old system stays reachable?
• Has a small pilot group tested mail, calendar, and file access before the full cutover?

Our Microsoft 365 administration service covers exactly this: staged migration with a defined cutover window, plus the security configuration most lift-and-shift migrations skip. Get in touch to talk through your current setup.