Migrating from Microsoft 365 to Google Workspace: step-by-step guide

Move from Microsoft to Google without losing data

Migrating from Microsoft 365 to Google Workspace is a structured project that unfolds in several phases. Emails, files, calendars and contacts are transferred without data loss or service interruption. This guide details the key steps and the pitfalls to avoid for a successful transition.

Phase 1: audit and preparation

The pre-migration audit inventories everything that needs to be transferred. Count the volume of emails per user, the size of mailboxes, the number of OneDrive/SharePoint files and shared calendars. Identify the third-party integrations that depend on Microsoft 365 (business applications, connectors, Excel macros).

Create a communication plan to inform users of the migration schedule. Resistance to change is the main risk of failure. Involve key users from the start and designate ambassadors in each team.

Configure your domain in Google Workspace and create the user accounts. Do not change the DNS records yet so that emails keep arriving in Microsoft 365 during the preparation.

Phase 2: data migration

Google provides a native tool, Google Workspace Migration for Microsoft Exchange (GWMME), which transfers emails, contacts and calendars from Exchange Online. The tool runs in the background and can migrate several users in parallel.

OneDrive and SharePoint files are transferred to Google Drive. Google also provides a dedicated tool for this migration. Sharing permissions are recreated in Google Drive to maintain existing access.

Migration is done through progressive copying. The most recent data is transferred first, then the tool works back through the history. This approach lets users start working in Google Workspace while older data is still being transferred.

Phase 3: DNS switchover

The DNS switchover is when emails start arriving in Google Workspace instead of Microsoft 365. This operation is done by changing your domain’s MX records. DNS propagation takes a few hours, during which emails arrive in both systems.

Plan the switchover for a Friday evening or a weekend to minimize the impact. Verify that all emails arrive correctly in Google Workspace before deactivating the Microsoft 365 mailboxes.

Phase 4: training and adoption

Training is the key to migration success. Users accustomed to Outlook, Word and Excel need support to adopt Gmail, Docs and Sheets. Organize short training sessions (1 to 2 hours) in groups of 10 to 15 people.

Focus the training on daily tasks: sending and organizing emails in Gmail, sharing files in Drive, collaborating in real time in Docs. Advanced features will come naturally with use.

Set up a dedicated support channel (email or chat) for the first weeks after the migration. Questions are numerous at the start and drop off quickly.

LCMH, a Google Workspace reseller in Alsace, manages the entire migration process for SMBs.

To compare the two suites, read our Google Workspace vs Microsoft 365 comparison.

Sources

1. Google, Migrate to Google Workspace. support.google.com/a/answer/6251069
2. Google, GWMME - Migration for Microsoft Exchange. support.google.com/a/answer/6003169
3. Google, Google Workspace Training. workspace.google.com/training