Table of contents
Technically, moving from Microsoft 365 to Google Workspace is a solved problem. Google’s Data Migration Service moves mail, calendars and contacts, and it works. Projects still go wrong, almost never for technical reasons.
What moves cleanly
- Email: full history, folders, attachments. Slow but reliable.
- Calendars: including recurring events and attendees.
- Contacts: no drama.
- OneDrive and SharePoint files: they transfer, and Office formats open and convert in Drive.
What does not move, and what to do about it
- Excel with macros, Power Query, complex models. Sheets will not reproduce them. Keep those as Excel files in Drive and hold a few Microsoft licences for finance. Sense, not defeat.
- Outlook rules and categories. They stay behind. People will rebuild them and complain. Budget the goodwill.
- Shared mailboxes. A Microsoft concept that maps to a different answer in Google: see shared inboxes.
- Apps welded to Outlook. Industry software that “sends from Outlook” can stop working. Test before the switch, not after.
Where downtime hides
The only moment mail can be lost is the MX record switch. Prepared properly, downtime is zero: mail starts arriving in Google while the old environment still runs, and a final sync sweeps the tail. Prepared badly, messages bounce or pile up in a server nobody watches. SPF, DKIM and DMARC must be ready before the switch: our authentication guide covers it.
A realistic timeline
- 10 to 30 users: a week of preparation, a weekend switch, a week of hand-holding.
- 30 to 150: two to three weeks in waves.
- 150+: pilot first. Never everyone at once.
The hardest part is not technical
It is people who have used Outlook for ten years. The first week brings complaints that “everything is different”, and most of it is habit, not fault. One hour of training before the switch, one champion per department, and a clear message from management that the first two weeks will be slower.
Under 20 users with no Excel macros? You can do this yourselves with Google’s documentation. More people, integrations, or no appetite for mistakes: we have done this regularly since 2012. Talk to us.
