Migrate Organization from Microsoft 365 to Google Workspace: Move Mailboxes, Emails, Contacts, Calendars & Files

Written By Harshita Sachdeva
Approved By
Shivam Rathore
Updated on October 9th, 2026

ⓘ Fact-checked and reviewed in accordance with our Editorial Policy

Alena, IT Administrator, Asked

Our organisation has used Microsoft 365 for many years (for all our daily work requirements); however, we have now chosen to move over to Google Workspace. Given that each employee’s account holds large volumes of calendar events, contact information, OneDrive files, SharePoint data, and Teams discussions, we are concerned about data integrity. Also, the large number of users in the organisation makes the migration process even more complex to execute. We are looking for a quick as well as dependable method to migrate organization from Microsoft 365 to Google Workspace. That too, in a way that the M365 data items are accurately mapped in Google Workspace folders.

Technical Overview: Microsoft is a widely used platform across organisations for business communication and productivity purposes. Irrespective of the scale of the organisation – SMB or a large firm- Microsoft is often used to manage emails, calendars, contacts, OneDrive files, SharePoint data, Teams conversations, and other business workloads. Once these enterprises shift to Google Workspace, they need to transfer all these existing workloads’ data to the corresponding Google services. Some use the Aryson Email Migration Tool to perform this migration. Whereas others choose the manual route. A suitable migration method might vary w.r.t. different aspects, so read this blog to the end to know your suitable method.

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Table of Contents

What Makes Organisational Migration Challenging?

When an organisational migration takes place, the number of users becomes just a part of it, not the entire migration. Hence, the migration process will become complicated w.r.t. the dataset volume, workloads, permissions, and the structure of the target account.

Workload Planning

Before you migrate from Office 365 to Google Workspace, create an inventory of the Microsoft 365 workloads and determine their Google Workspace destination.

Microsoft 365 Source	Google Workspace Target
Exchange Online mailboxes	Gmail
Outlook calendars	Google Calendar
Outlook contacts	Google Contacts
OneDrive	Google Drive / My Drive
SharePoint Online	Shared drives
Teams files	Google Drive / Shared drives
Teams chats/messages	Separate assessment
Microsoft 365 groups	Google Groups / other structures
Planner	Google Tasks, third-party solution, or recreation
Teams/SharePoint sites	Shared drives, Sites, or rebuilt structures
Outlook rules	Gmail filters/rules may require recreation
Mail-enabled/security groups	Google Groups / target groups

*It is not necessary that all Microsoft 365 workloads will be moved over to a very sort of Google Workspace service. Rather, a few of them might need restructuring, recreation or a completely different migration approach.*

1. Know What You Need to Migrate

Before you start the migration, create an inventory of all the data items you need to migrate organization from Microsoft 365 to Google Workspace. Track the services that are currently active, the dataset to be migrated, and the workloads you need to migrate separately.

2. User and Identity Mapping Is Critical

Map the source account to the destination account before you transfer data.

Source	Destination
john@company.com	john@company.com
sara@company.com	sara@company.com

Account for renamed users, departments, inactive accounts, shared/resource mailboxes, groups, multiple domains, and aliases. Maintain a CSV containing source user, target user, workload, destination, status, and exceptions. Identity mapping helps preserve relationships involving permissions, sharing, calendars, and ownership.

3. Assess Migration Workloads

Record all your active, inactive, shared, and resource accounts.
Find out the size of your mailboxes, OneDrive, SharePoint, and other data too.
Identify workloads requiring recreation or separate methods.
Prioritise critical departments and high-volume users.
Document application, permission, and group dependencies.

4. Plan Microsoft 365 to Google Workspace Migration Phases

Run a pilot with representative users.
Migrate IT users first.
Create batches by department, location, workload, or volume.
Distribute high-volume accounts across phases.
Define cutover dates and use delta migration where supported.
Check each batch of data migrated before you proceed further.

5. Prepare for Large Data Volumes

After this, before you schedule the migration, calculate the total amount of data that has to be migrated. It is recommended to have additional planning when you migrate 40, 000+ files to a user’s drive. Make sure you divide data in batches and allow time for retrying. Also, check whether the data migrated successfully in the accounts with high data volumes.

6. Validate the Target Environment

Before migration:

Create the required Google Workspace users.
Verify domains and aliases.
Create groups and Shared drives.
Confirm target storage.
Verify administrator permissions.
Test representative accounts.
Confirm destination structures.

How to Migrate Organization from Microsoft 365 to Google Workspace?

In this section, we will mainly discuss the top methods to transfer Microsoft 365 data to a Google Workspace account. Read through both of these methods and pick the one that suits your requirements as well as convenience.

Method 1: Manual Method to Switch From Microsoft to Google Workspace

Google Workspace Migrate provides an enterprise migration framework for supported source environments. Its workflow uses source and target connections, mappings, identity mappings, settings templates, and migration bridges. Mappings determine what content is migrated and where it is placed.

However, its current product lifecycle should be considered before selecting it for a new organisational migration. Google has clearly mentioned that SharePoint Online and OneDrive migration via Google Workspace Migrate is no longer being updated and no bug fixes have been received since September 15, 2026.

The steps to migrate Office 365 to Google Workspace are as follows:

Review which source workloads are supported by Google Workspace – and also its own requirements.
Prepare administrator access and required source connections.
Create source-to-destination identity mappings.
Create workload mappings for each migration phase.
Configure the required settings templates.
Create migration bridges using the configured mappings and connections.
Scan and validate each migration phase.
Start the migration and monitor transactions.
Perform delta migration where supported.
Validate your migrated data carefully – before you actually make the cut-over switch.

Where Does the Native Method Lag Behind?

Some limitations can affect an organisation-wide migration:

Identity preparation: Very large environments need precise source-to-target mapping details.
Migration configuration: You’ll have to configure connections, mappings, templates, and bridges.
Large datasets: High-volume workloads require additional phase planning.
Workload differences: Teams chats, Planner, and other Microsoft-specific workloads may require separate handling.
Migration lifecycle: Google Workspace Migrate has announced lifecycle changes for SharePoint Online, OneDrive, and Exchange Online.
Delta migration: Google documents that conflict detection and merging are not supported for certain file migrations. Destination changes can therefore be lost during migration.
Large Drive migrations: 400,000 or more files for one user require additional planning and load distribution.

Method 2: Professional Method to Migrate Organization from Microsoft 365 to Google Workspace

In order to avoid the limitations of the manual method, Aryson Email Migration Tool came up with a dedicated migration workflow. This graph API-based software is designed in such a way that there is no chance of loss of data or credentials along the way. Moreover, this utility provides a CSV import feature and admin mode of login to let enterprises migrate their large number of users’ data in just a few minutes/hours. The same tool can be used to migrate IMAP to Office 365, Google Workspace and many more clients as well. Even the mapping feature makes sure that the Microsoft 365 data is migrated to the intended destination only, that too without any effect on the structure of data.

How to Migrate Office 365 to Google Workspace with Aryson?

Download and launch the Aryson Email Migration Tool.
Select Microsoft 365 as the source.
Authenticate the Microsoft 365 source.
Select Google Workspace as the destination.
Authenticate the destination account via P12 or JSON key.
Import or configure the source-to-destination mapping.
Apply date, item-type, attachment, and duplicate filters.
Start migration for selected accounts or batches.
Monitor the migration progress and reports.
Validate the migrated Gmail data.

All the steps above will help you quickly migrate organization from Microsoft 365 to Google Workspace; however, it is better to read the complete manual of the software and then start migrating.

The tool also provides Skip Previously Migrated functionality for incremental migration and CSV processing for large-scale mailbox deployments.

Native Method vs. Aryson Email Migration Tool

Have a look at the below-given comparison before you migrate your organization from Microsoft to Google Workspace.

Migration Requirement	Native Google Workspace Method	Aryson Email Migration Tool
Microsoft 365 to Google Workspace email migration	Supported within applicable native workflows and lifecycle	Supported
Bulk mailbox migration	Requires migration configuration and phases	CSV-based bulk processing
Source-to-destination mapping	Identity and workload mappings required	Source-to-destination mailbox mapping
Large mailbox batches	Requires phase and workload planning	Batch processing for multiple accounts
Date-based migration	Depends on configured migration workflow	Date-range filtering
Item-type selection	Configured through migration settings	Selective item-type migration
Duplicate handling	Depends on migration workflow	Duplicate filtering/removal
Previously migrated data	Delta migration has workflow-specific limitations	Skip Previously Migrated option
Folder hierarchy	Depends on source workload and migration mapping	Preserves folder hierarchy
Migration monitoring	Bridges and migration monitoring	Progress tracking and migration reports
Exchange Online lifecycle	Support ends October 2026 in Google Workspace Migrate	Office 365 to Google Workspace migration supported

The native approach is designed around Google’s migration infrastructure and supported workloads. Whereas Aryson software is designed in a way to help enterprises with the migration process only.

Conclusion

When organisations migrate organization from Microsoft 365 to Google Workspace, the preliminary step is to understand the complete Office 365 environment. Proper planning is essential before the actual migration. Either the user chooses the professional method or opts for the manual route instead. Each of these methods would give results based on the underlying requirements and the structure of the entire organisation. Therefore, it is important to first migrate a test pilot batch, and once it delivers accurate results, perform migration on the remaining batches.

Frequently Asked Questions

Q.1 Does Google Workspace work with Office 365?

Ans: Yes. Google Workspace can work along with Office 365. This allows organisations to use both platforms. However, due to certain requirements of the organisations, the migration and integration of the services is performed.

Q.2 How to Migrate Emails from Microsoft 365 to Google Workspace?

Ans: You can either use the manual method or the Aryson Email migration software. Both methods work well on their own. But, for a more secure migration, it is recommended to use the Aryson Email Migration Tool.

Q.3 What is a good replacement for Office 365?

Ans: Users use Google Workspace as an alternative platform to Office 365. After this migration, users can use Gmail, Drive, Docs and other cloud-based services under one platform only. However, the right choice might vary with the requirements.

Q.4 Why is user mapping important in an organizational migration?

Ans: It is important to map the Office 365 data correctly to the Google Workspace mailboxes when there is a large amount of data associated with the source account. Also,
The data placement also plays a vital role in day-to-day activities.

Q.5 Can all Microsoft 365 workloads be migrated directly to Google Workspace?

Ans: Yes. With the help of the Aryson Email Migration Tool, it has become way more easier to directly migrate Microsoft 365 workloads to Google Workspace.

Q.6 How should I migrate a large number of Microsoft 365 users?

Ans: It is recommended to first divide the large volume of data into batches and then only perform the migration. Test the methods on a sample pilot batch and apply it afterwards on the remaining data.

Q.7 Can Aryson migrate multiple Microsoft 365 mailboxes to Google Workspace?

Ans: Yes. with the Admin login mode, you can migrate multiple mailboxes from multiple users in just one go. That too, without affecting the data integrity and structure of data.

Q.8 Can I migrate only selected Microsoft 365 mailbox data?

Ans: Yes. It is possible to migrate only the selecetd data from Microsoft 365 to Google Workspace if you use the professional software .

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About The Author:

Harshita Sachdeva

Harshita Sachdeva, a professional technical writer at Aryson Technologies, specialize in delivering clear, hands-on documentation for data management, migration, and recovery solutions. With a meticulous, reader-first approach, I break down complex technical processes into simple, actionable content - helping IT professionals and decision-makers tackle challenges efficiently.

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