Migrate G Suite to O365 with API

Tutorial on how to migrate G Suite to O365 with API instead of using IMAP which need to know credential for individual users’ mailbox

Sign in to Google Cloud Platform with the administrator credential for the Trial Account provisioned

Go to Dashboard – Down Arrow – New Project to create a new project

Enter a Project Name called GSuiteToO365 and click CREATE

Expand the Left Top Menu and go to IAM & Admin – Service Accounts – Create Service Account

Assign a Name for Google Service Account, like G2O365 with description and click CREATE to continue

Click Continue

Click DONE

Create a Private Key for Google Service Account

Select JSON and click CREATE

Save the Private Key (JSON file) as it is required when we create the mailbox migration batch in Office 365 later

Double click on the Google Service Accounts and copy the value of Unique ID. Click on SHOW DOMAIN-WIDE DELEGATION

Click EDIT to ENABLE G Suite Domain-wide Delegation. Enter a Name in Product Name for the consent screen and click SAVE

Enable Domain-Wide Delegation – Allows this service account to be authorized to access all users’ data on a G Suite domain without manual authorization on their parts

Go to APIs & Services – Library

Search for Gmail API, Google Calendar API & Contacts API

Click ENABLE to enable the API Usage for Gmail API, Google Calendar API & Contacts API

Sign in to G Suite Admin Page and go to Security – App Access Control. Click MANAGE DOMAIN-WIDE DELEGATION

Create a new Client ID with

• Client ID = Unique ID of Google Service Account created
• OAuth Scopes = https://mail.google.com/,https://www.googleapis.com/auth/calendar,https://www.google.com/m8/feeds/,https://www.googleapis.com/auth/gmail.settings.sharing

Click AUTHORISE to add the new Client ID

Verify the API Client is created successfully

Connect to Office 365 with PowerShell to test connectivity between G Suite and Microsoft 365 with JSON file and Admin Account for G Suite

Test-MigrationServerAvailability -Gmail -ServiceAccountKeyFileData $([System.IO.File]::ReadAllBytes("C:\\temp\\gsuitetoo365-281817-28cc5c8d308a.json")) -EmailAddress [email protected]

RunspaceId      : 294a8e67-a33f-499f-b780-5e320670aa63
Result          : Success
Message         : 
SupportsCutover : False
ErrorDetail     : 
TestedEndpoint  : [email protected]
IsValid         : True
Identity        : 
ObjectState     : New

Create a New Migration EndPoint called GmailEndPoint

New-MigrationEndpoint -Gmail -ServiceAccountKeyFileData $([System.IO.File]::ReadAllBytes("C:\\temp\\gsuitetoo365-281817-28cc5c8d308a.json")) `
-EmailAddress [email protected] -Name GmailEndPoint

Export all users & groups from Google G Suite by referring to Manage Google G Suite with PowerShell

Provision Users & Groups in Office 365 from the exported CSV file

Prepare a CSV file contain user’s email address as below and save it as C:\temp\MigrateUsers.csv

EmailAddress
[email protected]
[email protected]

Create a new Migration Bath to migrate uat1 & uat2 from G Suite to Office 365

New-MigrationBatch -SourceEndpoint GmailEndpoint -Name Batch-20200723 -CSVData $([System.IO.File]::ReadAllBytes("C:\temp\MigrateUsers.csv")) `
-TargetDeliveryDomain "M365x510625.onmicrosoft.com"

Start-MigrationBatch -Identity "Batch-20200723" 

It might take some time to complete the sync depend on the mailbox size and it will synchronize every 24 hours

Get-MigrationBatch

Identity       Status Type  TotalCount
--------       ------ ----  ----------
Batch-20200723 Synced Gmail 2   

Login to Office 365 portal using uat1 or uat2 to verify all mail, calender and contact had been syned from G Suite to Office 365 successfully

Lastly, you can change the MX record to point to Office to complete the migration from G Suite to Office 365.