Migrate mail from Google Accounts or IMAP

G Suite Migration for Microsoft Exchange

After you create a Google Workspace account, you can migrate email data from your old Google or IMAP-based email account using G Suite Migration for Microsoft Exchange (GSMME). You can choose to migrate data using one of the following methods:

  • Gmail—Migrate data using IMAP. Provides configuration presets to make migration simpler.
  • IMAP—Migrate from nearly any RFC 3501-compliant IMAP server. Provides more options for greater control over the migration.

To learn more about GSMME, the GSMME Admin Guide includes detailed information on how GSMME works, getting started, and running your migration.

Step 1: Before you begin

Check the system requirements
Make sure you meet the GSMME system requirements.
Check whether you need to allow access for less secure apps

Allow permissions for less secure apps to access accounts:

  1. If you're migrating from a Google Workspace account and are using a password instead of OAuth. For details, go to "Option 1" on Authorize GSMME for your account.
  2. If you're migrating from a personal Gmail (@gmail.com) account.

    Note: When migrating from Gmail accounts, we recommend using the data migration service as it doesn't require permission for less secure apps. Learn more

For more information, go to Control access to less secure apps.

Note: Accounts that have 2-Step Verification turned on don’t have the less secure apps setting. Instead, use App Passwords.

Turn off folder-size limits and make labels available

Each user must individually turn off folder-size limits and make the All Mail, Spam, and Trash labels available to IMAP.

  1. To turn off folder-size limits, each user must:
    1. Open Gmail and click Settings "" and then See all settings.
    2. On the Forwarding and POP/IMAP tab, make sure Enable IMAP is selected.
    3. Select Do not limit the number of messages in an IMAP folder (default) under Folder size limits and click Save Changes.
  2. To show All Mail, Spam, and Trash labels in IMAP, each user must:
    1. Open Gmail and click Settings "" and then See all settings.
    2. On the Labels tab, next to All Mail, Spam, and Trash, check the Show in IMAP box.
Create a CSV file of users
Create a control CSV file of the user accounts you’re migrating to make sure your legacy data correctly maps to your new user accounts. The format of the control CSV file depends on the system from which you’re migrating. Learn more

Step 2: Authorize GSMME

Before you can install GSMME, you must authorize the software for your domain. For details, go to Authorize GSMME for your account.

Step 3: Download and install GSMME

  1. Download the MSI file from the GSMME download page.
  2. To install GSMME, open the installer and follow the instructions.

Step 4: Configure GSMME

Complete these steps in the GSMME product.

Step 1: IMAP server details
  1. Run GSMME: Click Start and thenG Suite Migration and thenG Suite Migration for Microsoft Exchange.
  2. For Server Type, select IMAP or Gmail.

    Note: If you select Gmail, no extra details are required. Click Next to go to Step 2.

  3. For IMAP Server Type, select the server type that applies to your migration.
  4. In the Hostname/IP Address field, specify your source domain name or the IP address of the email server from which you want to migrate data. For example: imap.example.com or 198.102.434.8.
  5. Select your IMAP Security preference.
  6. Enter your IMAP Port value. If you're using SSL, specify 993.
  7. If you're migrating from a Cyrus or Courier IMAP server, specify INBOX in the IMAP Path Prefix field. Otherwise, leave it blank.
  8. Click Next to specify user and domain information.
Step 2: User and domain information
  1. In the G Suite domain name field, specify the new primary Google Workspace domain where the data will be migrated.

    Note: The domain you specify in step 1 of the GSMME product must be the primary Google Workspace target domain environment you're migrating users to. If you're migrating mail to a Google Workspace account with secondary domains, the target domain you choose might differ from the domain in the email addresses you’re migrating.

  2. In the Service account credentials file field, specify the path to your credentials JSON file created as part of the authorization process.
  3. In the G Suite admin user field, specify the full email address of your Google Workspace domain super administrator.
  4. Click Next to specify the migration settings.
Step 3: Migration settings
  1. Check the Email messages box and set the date range for the migration. For details, review Chapter 5 in the GSMME Admin Guide.
  2. In the File of accounts to migrate field, specify the path to the CSV file of user accounts you’re migrating.
  3. Click Next.
  4. Review the migration settings and optionally make changes.
  5. Select your migration actions:
    • Migrate all data—When checked, the utility overwrites existing data during migration. When unchecked, duplicate messages are skipped.
    • Save settings—When checked, the utility keeps the current configuration for future use.
    • Run Diagnostics—When checked, the utility verifies the configuration before running the migration.
    • Estimate—When checked, the utility estimates the message count for the source users.
    • Migrate—When checked, the utility runs the migration.
  6. Click Next to begin the migration process.
  7. If Run Diagnostics is checked, test results are displayed. Click Start to begin the migration process once all tests pass.


Google, Google Workspace, and related marks and logos are trademarks of Google LLC. All other company and product names are trademarks of the companies with which they are associated.

Was this helpful?
How can we improve it?

Need more help?

Sign in for additional support options to quickly solve your issue