Migrate from Microsoft 365 to Google Workspace: The Complete Guide

Many organisations leave Microsoft 365 for Google Workspace to get a lighter inbox, unified collaboration tools (Gmail, Calendar, Drive, Docs) and clearer billing. The good news is that Exchange mailboxes, calendars, contacts and OneDrive/SharePoint files can be moved without losing a single email or interrupting delivery — as long as you follow the right order and keep both platforms running during the cutover.

What gets migrated — and why people switch

A business email migration is about far more than the messages. Several data types need to move, each with its own constraints:

• Emails: entire Exchange Online mailboxes, including folders, sub-folders and labels, with original dates preserved.
• Contacts: personal address books and shared lists.
• Calendars: appointments, invitations, recurring events and shared calendars.
• Files: documents stored on OneDrive for Business and SharePoint sites, to be moved to Google Drive and shared drives.

People switch for Gmail's simplicity, real-time collaboration in Docs and Sheets, clearer pooled storage and a predictable per-user cost. Whatever the reason, the goal is the same: users find their complete history on Monday morning, having lost nothing.

Step 1 · Audit what you have before touching anything

A successful migration starts with a precise inventory. Take the time to list:

• the number of mailboxes to migrate and their size (a 50 GB mailbox does not move in the same window as a 2 GB one);
• shared mailboxes, distribution lists and aliases;
• the domain and its registrar, plus the current DNS/MX records and above all their TTL — lower it to 300 seconds a few days before cutover to speed up propagation;
• OneDrive/SharePoint files and their sharing permissions.

This audit drives the timeline: the larger the volume, the earlier you should start and the longer you let the sync run in the background.

Step 2 · Provision Google Workspace

Create the Google Workspace tenant, then verify domain ownership in the admin console (via a TXT record at your registrar). Recreate the user accounts — ideally with the same addresses as in Microsoft 365 so nothing changes for correspondents — the groups, the shared drives and the security rules (two-step verification, password policies). Do not change the MX records yet: at this stage, mail still lands on Microsoft 365.

Step 3 · Migrate email, calendars and contacts

Google provides the official tool for this transfer: the Data Migration Service (DMS), built into the admin console. It connects to Microsoft 365 over Exchange Web Services (EWS) and copies emails, calendars and contacts straight into Gmail and Google Calendar. For larger estates, Google Workspace Migrate orchestrates bigger batches and tracks each mailbox.

The principle is a background sync: it starts while Microsoft 365 is still receiving mail, then a final delta pass catches messages that arrived in the meantime. That way, no downtime window is imposed on users.

Step 4 · Move OneDrive and SharePoint files to Drive

For files, two complementary approaches. For small volumes, download folders from OneDrive/SharePoint and re-upload them to Google Drive using the Google Drive for desktop client. For a whole estate, Google Workspace Migrate transfers documents and SharePoint libraries into shared drives while preserving the folder tree. Always re-check permissions afterwards: a company-wide share on SharePoint does not automatically translate into an equivalent Drive share.

The secret to a zero-downtime cutover: never turn off the source until the destination is verified. Both mailboxes coexist for a few days while mail finds its new route.

Step 5 · Switch DNS/MX without downtime

Once the initial sync is done, change the domain's MX records to point to Google Workspace. Also add the SPF record, the DKIM key generated by Google and a DMARC policy to protect deliverability. Thanks to the TTL you lowered in Step 1, propagation usually takes a few dozen minutes; during that window both platforms may receive messages, which is why you keep Microsoft 365 active for another day or two.

Step 6 · Verify and reconfigure clients

After cutover, confirm that a test email lands in Gmail and that calendars are complete. Then reconfigure clients: in Outlook, you can add the account via Google Workspace Sync for Microsoft Outlook (GWSMO), or move users straight onto the Gmail interface. On mobile, replace the Exchange account with a Google account. Remember to update signatures, filters and calendar shares.

Common pitfalls

• Rate limits: Microsoft and Google both enforce access quotas; a very large mailbox can take several hours — plan generously.
• Duplicates: re-running a full migration instead of a delta duplicates messages. Always use incremental mode.
• Recurring calendars: complex event series or badly set time zones can shift — check them first.
• Sharing permissions: OneDrive/SharePoint rights do not map one-to-one; re-verify sensitive access.
• Aliases and shared mailboxes: recreate them on the Google side before cutover to avoid bounces.

How much it costs: Yuna7 vs an IT contractor

Having a contractor migrate Microsoft 365 to Google Workspace often costs several hundred dollars, with quotes and lead times. Yuna7 automates the cutover and you only pay for what you actually use — you can even try it for free.

Let Yuna7 migrate Microsoft 365 to Google Workspace for you

Describe your migration in one sentence: Yuna7 audits your mailboxes and domain, provisions Google Workspace, runs the Data Migration Service for mail, calendars and contacts, moves your OneDrive/SharePoint files to Drive, switches the DNS/MX records at the right moment and verifies everything arrived — you simply approve the sensitive steps. Far cheaper than a technician, and launched in minutes.