Google Workspace (G Suite) to Office 365 Migration Using IMAP

Organizations that use Google Workspace (formerly G Suite) may decide to move business email to Microsoft 365 when they want Exchange Online, Outlook, Teams, OneDrive, SharePoint, and Microsoft 365 administration in a single environment. EdbMails provides an IMAP-based migration workflow to transfer Gmail mailbox data from Google Workspace to Office 365.

Migration scope: IMAP migration is designed for email data. It can migrate messages, attachments, folders or Gmail labels exposed through IMAP, and supported message metadata. Contacts, calendars, Google Drive files, and other Google Workspace workloads are not migrated through IMAP and require a separate migration method.

The EdbMails IMAP Migration Tool connects the Google Workspace source with the Microsoft 365 target and supports single-user and bulk mailbox migration, mailbox mapping, filtering, incremental follow-up runs, migration reports, and 24/7 free technical support. It is designed to preserve supported email content, attachments, folder hierarchy, and common message properties where the source exposes them and Microsoft 365 accepts them.

For destination-wide planning, prerequisites, Microsoft 365 authentication, mapping, and cutover guidance, use the main IMAP to Office 365 migration guide.

1. Google Workspace to Office 365 Migration Planning

   • Identify the Google Workspace mailboxes and approximate mailbox sizes to migrate.
   • Confirm that IMAP access is permitted for the required Google Workspace users and that the organization’s authentication policy allows the migration connection.
   • Create the target Microsoft 365 users or mailboxes and assign the required licenses.
   • Add and verify the custom email domain in Microsoft 365 if the same business domain will be retained after migration.
   • Decide whether to migrate all mailboxes together or in controlled batches.
   • Run a pilot migration with a small set of users before the production migration.
   • Plan the final DNS / MX record change only after the target mailboxes and migrated data are verified.

2. Prerequisites for Google Workspace to Office 365 IMAP Migration

   Google Workspace source:

   • Ensure IMAP access is allowed for the Google Workspace users being migrated. Google Workspace administrators can manage IMAP access in the Admin console under Gmail end-user access settings.
   • Google Workspace no longer supports legacy “less secure app” sign-in. Use an authentication method permitted by your Google Workspace security policy and supported by the migration connection.
   • Make sure the Gmail labels or folders that must be migrated are available through IMAP.
   • For bulk migration, prepare the source mailbox information required by the EdbMails CSV workflow.

    Google Workspace: manage POP and IMAP access for users

   Microsoft 365 target:

   • Create the required Microsoft 365 users and Exchange Online mailboxes and assign suitable licenses.
   • Configure the target connection using the Microsoft 365 OAuth-based connection method supported by EdbMails.
   • Add and verify your custom domain if it will be used for email in Microsoft 365 after migration.
   • Review mailbox size, network bandwidth, throttling, and migration-window requirements before moving large mailbox batches.

3. Steps to Migrate Google Workspace to Office 365 Using IMAP

   • Step 1: Download and install EdbMails

     • Download and install EdbMails on a supported Windows computer that can connect to both source and target environments.

        Review the IMAP migration system requirements.

       

     • Launch EdbMails and sign in with your registered EdbMails account. New users can choose ‘Start Your Free Trial’.
       Note: The trial allows migration of up to 30 items per folder. Purchase an IMAP Migration license for migration without the trial item limit.

        View IMAP Migration pricing.

       

     • Select ‘IMAP (Gmail, Outlook & more) Migration’.

       

     • Select ‘IMAP to Office 365 Migration’.

       

     • Use the default job name or create a new job name for the Google Workspace migration.

       

   • Step 2: Connect the Google Workspace source mailboxes

     • For one mailbox, choose ‘Single User / Account Migration’. For multiple mailboxes, choose ‘Multiple (Bulk) Users/Accounts Migration’.

       

     • Use Gmail’s IMAP server details for the source account and provide the authentication credential permitted by your Google Workspace configuration. If your administrator restricts IMAP clients, ensure the required client is allowed before connecting.
     • For bulk migration, download the EdbMails IMAP CSV template and enter the source mailbox details required by the application.

       

     • Load the completed CSV file and verify the Google Workspace source connections.

       

   • Step 3: Select Google Workspace mailboxes and folders

     • Select the mailboxes or folders you want to migrate to Microsoft 365 and click ‘Next’.

       

   • Step 4: Connect to the target Office 365 server

     • Click ‘Add New Connection’, or choose an existing configured Microsoft 365 connection.

       

     • Select the required target mailbox type and proceed with the Microsoft 365 OAuth-based connection method.

       

     • Authenticate on the official Microsoft sign-in page.

       

     • Load the target Microsoft 365 mailboxes automatically, from a CSV file, or from a previously saved list.

       

   • Step 5: Map Google Workspace mailboxes to Office 365

     • Choose the required mapping option and match each Google Workspace source mailbox with the correct Microsoft 365 target mailbox.

       

     • Review the mapping before beginning the migration.

       

   • Step 6: Start Google Workspace to Office 365 migration

     • Click ‘Start Migration’ after verifying the mailbox mapping.

       

     • Use ‘View Logs’ to review the migration status, folder-level item counts, and migration results.

       

4. Google Workspace to Office 365 Post-Migration Tasks

   • Verify migrated data: Compare representative mailboxes, folders, attachments, and item counts between Google Workspace and Microsoft 365.
   • Run an incremental pass if required: Migrate newly received or changed email items before final cutover.
   • Update DNS / MX records: After the target environment is verified, update the required DNS records so new email is delivered to Microsoft 365.
   • Validate Outlook and web access: Confirm users can sign in and access their Microsoft 365 mailboxes from the required clients.
   • Retain the Google Workspace source: Keep the source available until business verification and the agreed retention period are complete.

5. Troubleshooting Google Workspace to Office 365 IMAP Migration

   For migration issues, review the IMAP migration knowledge base, the IMAP migration FAQs, or contact EdbMails support.

 Learn more about the EdbMails IMAP Migration Tool.

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Additional resources:

• Gmail to Office 365 migration guide
• IMAP to Office 365 Shared Mailbox migration
• EdbMails IMAP migration software
• Office 365 migration filter settings
• Load Office 365 mailboxes using CSV