Plenty of businesses start on Google Workspace and outgrow it. Usually the trigger is the desktop Office apps, a client or partner that works entirely in Microsoft, or the device management and security tools in Microsoft 365 Business Premium. The move itself is very manageable, provided it is planned rather than rushed over a weekend.
Here is the order we work in, and what tends to catch people out.
1. Take an inventory before touching anything
A migration is only as good as the list behind it. Before anything moves, write down:
- Every user, including people who have left but whose mailbox is still needed
- Groups and shared inboxes, such as info@ or accounts@, and who reads them
- Aliases and forwarding rules, which are easy to forget and painful to lose
- Shared drives in Google Drive, and roughly how much data sits in each
- Anything that signs in with Google, such as accounting software, CRMs or scheduling tools that use “Sign in with Google” and will need a new sign-in method
- Google Sites, Forms and scripts, which do not migrate automatically and need a plan of their own
2. Set up the Microsoft 365 tenant properly
Create the tenant in the business’s own name, verify your domain with a DNS record, and assign licences. This is also the moment to put the security baseline in place, such as multi-factor authentication, admin roles and sharing settings, so staff arrive in a tenant that is already set up correctly rather than one that needs fixing later.
3. Copy mail, calendars and contacts ahead of time
Exchange Online includes a built-in migration for Google Workspace that copies mail, calendars and contacts. Specialist migration tools are an alternative for larger or more complicated moves. Either way, the bulk of the copying happens in the background during the days before cutover, while staff keep working in Gmail as normal.
Worth knowing: Gmail labels become folders in Outlook. A message with several labels can appear in several folders, which surprises people who relied heavily on labels.
4. Move Google Drive into OneDrive and SharePoint
Personal Drive files belong in each person’s OneDrive. Shared drives belong in SharePoint, usually one site per team or department, connected to the matching Team in Microsoft Teams. Microsoft’s Migration Manager can move Google Drive content and convert Google Docs, Sheets and Slides into Word, Excel and PowerPoint files along the way.
This is also the best chance you will get to tidy up. Old project folders and duplicates can be archived rather than carried across.
5. Plan the cutover for a quiet moment
A few days before cutover, lower the time-to-live on your MX record so the change spreads quickly. At cutover, typically on a Friday evening:
- Point the MX record at Microsoft 365
- Run a final sync to catch anything that arrived in the meantime
- Update SPF, then enable DKIM for Microsoft 365, and review DMARC
- Test sending and receiving to and from outside addresses
Staff may see a short delay while DNS updates. They should not see missing mail.
6. Get people working on Monday morning
Most of the anxiety in a migration comes from the first hour on day one. Help staff sign in to Outlook on their computers, add the Outlook and Teams apps to their phones, and show them where their files now live. Email signatures, mail filters and some delegation settings usually need recreating, so have a short list ready.
7. Keep Google for a short overlap, then close it cleanly
Do not cancel Google Workspace the moment mail starts flowing into Microsoft 365. Keep it for a few weeks as a safety net, confirm nothing is missing, export anything you are legally required to keep, then cancel. Remember to switch any third-party apps away from “Sign in with Google” before accounts are deleted.
Common mistakes
- Cancelling Google too early, before every shared drive and mailbox has been checked
- Forgetting shared inboxes and aliases, so replies to info@ disappear
- Leaving SPF pointing at Google, which sends outgoing mail to spam
- Moving a messy Drive as-is, then blaming SharePoint for being confusing
If you would like a second pair of hands, our Microsoft 365 migration service covers planning, the mail and file moves, DNS and first-morning support.