Migrate from Microsoft 365 to Google Workspace: Step-by-Step Guide (2026)

If your business is making the switch from Microsoft 365 to Google Workspace, you’re not alone — and you’re probably weighing the same questions every SMB owner asks: how long will this take, will my team lose email history, and how do I avoid weeks of messages landing in spam?

In our previous article, we covered how to migrate from Google Workspace to Microsoft 365. This guide walks through the reverse journey — moving your mailboxes, calendars, contacts, and files from Microsoft 365 over to Google Workspace — with a clear, non-technical roadmap you can actually follow.

Why Businesses Switch from Microsoft 365 to Google Workspace

Most companies we work with cite a few recurring reasons for making this move:

  • Simplicity. One login, one bill, one connected ecosystem — Gmail, Drive, Meet, Chat, and Calendar all work together natively, without juggling separate apps for mail, files, and chat.
  • Real-time collaboration. Google Docs, Sheets, and Slides offer smoother simultaneous editing than Microsoft’s web apps, which matters for teams that co-write documents constantly.
  • Cost predictability. Microsoft licensing can creep upward once a team needs E3 or E5-level features; Google Workspace Business Standard often covers the same needs at a flatter price point.
  • Reduced tool sprawl. Teams often tell us that SharePoint and OneDrive overlap confusingly, while Teams and Outlook compete for the same conversations. Google Workspace consolidates this into fewer, clearer tools.

Whatever your reason, the migration itself is manageable with the right plan — and the biggest risk isn’t technical failure, it’s skipping prep work that prevents deliverability problems later. Looking for a detailed breakdown of professional email migrations? Check out our comprehensive Email Migration guide, written by industry experts.

Step 1: Assess Your Data and Plan the Migration

Before touching any settings, inventory what you’re moving:

  • Total number of users, mailboxes, and shared mailboxes
  • Mailbox sizes (to anticipate migration time and tool limits)
  • Calendars, contacts, and distribution lists
  • Files in OneDrive and SharePoint, including total volume and folder structure
  • Any custom domains, aliases, or shared inboxes (info@, support@, etc.)

This inventory does double duty: it tells you which migration tool fits your size, and it gives you a baseline to validate against once the migration completes — so you know nothing was left behind.

How long should you expect this to take? As a rough guide:

Team Size Estimated Migration Timeline
1–10 users A weekend
10–50 users 1–2 weeks, with parallel running
50–200 users 2–4 weeks, phased by department

Step 2: Set Up Google Workspace Before Migrating Anything

Don’t migrate a single mailbox until your destination is ready. This means:

  1. Sign up for Google Workspace (Business Standard fits most SMBs, but choose the plan that matches your storage and security needs).
  2. Verify your domain by adding the TXT record Google provides to your DNS — but don’t touch your MX records yet.
  3. Create every user account and alias in the Google Admin Console first, matching email addresses exactly to your Microsoft 365 setup. Migration tools need a matching account on the Google side before they can deliver data.
  4. Set up groups and shared drives that will receive shared mailbox or shared folder content.
  5. Configure SPF, DKIM, and DMARC records before switching MX records. This is the step most DIY migrations skip — and skipping it is the most common reason emails start landing in spam after a switch.
  6. Enforce two-factor authentication, ideally with a 1–2 week grace period so staff can set up authenticator apps before it becomes mandatory.

Step 3: Choose the Right Migration Tool

The tool you need depends on what you’re migrating and how many users are involved.

  • Google Workspace Migration for Microsoft Outlook (GWMMO): Best for very small or do-it-yourself migrations (roughly 1–20 users) where each person is comfortable clicking through a wizard themselves.
  • Google Workspace Migration for Microsoft Exchange (GWMME): Suited to small and mid-sized migrations where mail, calendars, and contacts need to move and you want to manage the process centrally rather than relying on end users.
  • Google Workspace Data Migration Service (DMS): Built into the Google Admin Console under Account > Data migration. You select Microsoft Office 365 as the source, authorize with OAuth 2.0 (no TLS certificates required anymore), and choose which data types — email, calendar, contacts — to migrate. This is a solid default for most SMB migrations.
  • Google Workspace Migrate: Designed for enterprise-scale projects that also need to move Drive files, SharePoint libraries, OneDrive content, and fine-grained sharing permissions — typically for migrations beyond roughly 1,000 users or those involving complex file structures.

For most SMBs reading this guide, DMS handles mail, calendar, and contacts well, while file migration from OneDrive and SharePoint may need a dedicated content migration tool if your team relies heavily on shared drives.

Step 4: Run the Migration with a Transition Period

Don’t flip a switch overnight. Keep Microsoft 365 active throughout the migration so:

  • Users can keep working uninterrupted
  • A delta sync can capture changes made during the migration window
  • You have a safety net if something needs to be re-pulled

Set up dual delivery first. In Microsoft Exchange Online, create a transport rule that redirects external mail to your new Google Workspace domain, scoped tenant-wide so it applies across all accounts. Alternatively, create a mail-routing subdomain (e.g., gw.yourcompany.com) pointed at Google’s mail servers, so Google Workspace can begin receiving mail before you cut over your primary domain’s MX records.

Then run the actual data transfer through your chosen tool — DMS, GWMME, or Google Workspace Migrate — migrating mail, calendars, contacts, and files in batches rather than all at once if you have a larger team.

Step 5: Sync Calendars During the Transition

There’s no native way to achieve true two-way calendar sync between Microsoft 365 and Google Workspace during a transition period. If staff will be working across both platforms even briefly, a calendar sync tool that integrates with both Outlook and Google Calendar will prevent double-booking and missed meetings until the cutover is complete.

Step 6: Cut Over DNS and Validate

Once data has migrated and you’ve spot-checked it:

  1. Update your MX records to point to Google Workspace, completing the cutover.
  2. Check the message trace in Google Workspace’s Admin Console to confirm mail flow parity with what Microsoft 365 was handling.
  3. Spot-check mailboxes across departments — verify attachments, folder structures, and labels migrated correctly.
  4. Validate calendars, especially recurring meetings and shared calendars, for timezone or duplication issues.
  5. Confirm contacts migrated without duplication or corruption, particularly shared contact lists.
  6. Review Drive content if OneDrive or SharePoint files were part of the migration — check that folder structures and permissions carried over intact.

Step 7: Decommission Microsoft 365

Once you’ve confirmed data integrity and given your team a reasonable buffer period (we recommend at least one to two weeks of dual access):

  • Disable mailboxes in Exchange Online
  • Remove unused Microsoft 365 licenses to stop billing
  • Decommission Azure AD app permissions you no longer need
  • Reconfigure any third-party integrations that relied on the Microsoft Graph API to instead use Google Workspace APIs

Common Migration Pitfalls to Avoid

  • Skipping SPF/DKIM/DMARC setup before the MX cutover — the single most common cause of post-migration deliverability problems.
  • Not auditing file sizes and names beforehand. Files over certain size limits or with special characters can fail during transfer; clean these up before migration day.
  • Migrating with MFA fully enabled on the service account. Some migration tools don’t support 2FA/SSO on the admin account performing the migration — plan around this with app passwords or OAuth delegation where supported.
  • No transition period. Cutting over all at once, with no dual-running window, leaves no safety net if something goes wrong.
  • Forgetting SharePoint. SharePoint doesn’t have a direct Google Workspace equivalent — content moves into Google Drive, but site-specific functionality may need to be recreated using Google Sites or other tools.

FAQ

How long does a Microsoft 365 to Google Workspace migration take? For teams of 1–10 people, often a single weekend. For 10–50 users, plan for 1–2 weeks with both platforms running in parallel. For 50–200 users, expect 2–4 weeks with a phased, department-by-department rollout.

Will my team lose email history when switching from Outlook to Gmail? No, not if the migration is planned correctly. Tools like Google Workspace’s Data Migration Service transfer existing mail, calendars, and contacts, and a transition period with dual delivery ensures no new mail is lost during the switch.

Do I need to change my domain to migrate to Google Workspace? No. You can keep your existing domain and simply update your DNS records (MX, SPF, DKIM, DMARC) to point to Google Workspace instead of Microsoft 365.

What happens to my OneDrive and SharePoint files? Files can be migrated into Google Drive and shared drives. Google Workspace can open and edit Office file formats directly, or you can convert them to Google Docs, Sheets, and Slides formats for better real-time collaboration. SharePoint-specific site functionality doesn’t have a direct equivalent and may need to be rebuilt using Google Sites.

Can users access both Microsoft 365 and Google Workspace during the migration? Yes, and we recommend it. Just be aware that once the initial migration window closes, changes made in one platform won’t automatically sync to the other — which is why a defined transition period with validation checkpoints matters.

Considering a Microsoft 365 to Google Workspace migration for your business?

Manually planning DNS cutovers, validating mailbox data, and avoiding deliverability pitfalls takes time most SMB owners don’t have. EMNMS handles the entire migration process — from inventory and tool selection through DNS cutover and post-migration validation — so your team experiences zero data loss and minimal downtime. Get a free migration assessment from EMNMS →

Need to migrate from Google Workspace to Microsoft 365? Check out our guide: How to Migrate from Google Workspace to Microsoft 365 (Step-by-Step Guide)