Google Workspace to Microsoft 365 Migration Checklist

Introduction

Moving from Google Workspace (Gmail, Drive, Calendar) to Microsoft 365 (Outlook, OneDrive, Teams) is one of the most common switches we support for Southeast Asian SMEs. The goal is simple: keep mail history, calendars, and files — with a planned cutover so users are not surprised on Monday morning.

For a strategic comparison before you migrate, read Microsoft 365 vs Google Workspace.

What you are actually moving

Users will need training on Outlook and Teams even if data migrates perfectly.

Pre-migration checklist

1. Inventory mailboxes — count users, shared mailboxes, aliases
2. Measure Drive data — large shared drives need time and bandwidth
3. List integrated systems — CRM, accounting, scanners that send via Gmail SMTP
4. Buy Microsoft 365 licenses — assign before cutover (how to buy)
5. Verify domain — add DNS records to Microsoft 365; lower TTL a day early

Recommended migration phases

Phase 1 — Pilot (5–10 users)

• Migrate mail and calendar for IT plus friendly testers
• Validate Outlook desktop/mobile, Teams, and MFA
• Fix SPF/DKIM/DMARC for outbound mail from Microsoft

Phase 2 — Staged batches

• Move departments in waves (e.g. finance, then sales)
• Use dual delivery or forwarding only as a temporary bridge — not forever

Phase 3 — Cutover weekend

• Final delta sync for mail
• Switch MX records to Microsoft 365
• Communicate: "Send from Outlook starting Monday; Gmail read-only"

Phase 4 — Drive and collaboration

• Migrate high-value Shared drives to SharePoint or OneDrive
• Recreate shared links — Google share URLs will not redirect automatically

We document these phases in more detail on our migration services page.

DNS and downtime

MX cutover is the main downtime risk:

• Lower TTL on DNS 24 hours before
• Schedule cutover in local evening (ICT/SGT)
• Run final sync, then update MX to *.mail.protection.outlook.com (exact value from your tenant)

With planning, inbox downtime is typically hours, not days.

Licensing during migration

You need a Microsoft 365 license for every migrated user before they sign in to Outlook with your domain. Common choices:

• Business Standard — office workers
• Business Basic — web-first teams
• Business Premium — if Intune and endpoint security are required on day one

Common mistakes

• Migrating without enabling MFA — security gap on day one
• Leaving Google as MX for weeks — dual delivery confusion
• Ignoring shared mailboxes and distribution lists
• Assuming Google Forms/ Sites migrate — they do not; plan replacements

When to get professional help

Consider scoped migration support if you have:

• 50+ mailboxes or 500 GB+ Drive data
• Compliance retention requirements
• Hybrid coexistence with on-premises Exchange

Contact us with mailbox counts and go-live date for a migration quote alongside licensing.

Next steps

• Compare M365 vs Google
• Migration services
• Plan finder