Migrate data from PST files

Google Workspace Migration for Microsoft Exchange

You can use Google Workspace Migration for Microsoft Exchange (GWMME) to migrate email, calendar, or contact data to Google Workspace accounts from PST files through the GWMME interface or the command line. You can also apply your organization's Google Vault retention rules and holds to emails migrated from PST files without adding the messages to users' Gmail inboxes.

Notes for PST files and Vault

If you decide to make emails migrated from PST files (using GWMME's Migrate to Google Vault setting) subject to Vault, keep in mind:

  • Migrated messages don't appear in users’ Gmail inboxes.
  • Folder information is removed from messages before they’re migrated, so they won’t have labels in Vault.
  • GWMME doesn't overwrite or check for duplicate messages previously migrated to Vault.
  • Target users must have the Gmail service turned on.
  • Migration to Vault Former Employee (VFE) licensed users will be unsuccessful (because Gmail isn't turned on for these users).
  • For more information on Vault, go to the Google Vault Help Center.

Before you begin

  1. Make sure your GWMME client machine is using a supported version of Microsoft Outlook. If possible, make sure the Outlook version is the same or newer to the one used to create the PST file. Learn more
  2. Create a control CSV file for user accounts. Learn more

    If you're migrating calendar events, you might need to create a mapping CSV file. Learn more

  3. Next, authorize GWMME for your account.
  4. Turn off password protection, and allow read and write permissions on each PST file.
  5. Prepare the PST folder structure:
    1. Set up a top-level folder.
    2. Within that top-level folder, create an individual folder for each user whose PST files you want to migrate.
    3. Name the individual folders the same as the primary email addresses in the legacy environment. For example, if your source environment email addresses are user1@example.com and user2@example.com, then name your individual folders user1@example.com and user2@example.com.
    4. Place the PST files within the individual folders.


      C:\PST (top-level folder)
      user1@example.com (user folder)
      Mail.pst (PST file)
      Archive.pst (PST file)
      user2@example.com (user folder)
      Archive.pst (PST file)

Note: When you migrate mail folders, the email is labeled with the PST filename. To avoid this, migrate using the command line and specify the --noenable_label_prefix argument.

Migrate your data

Use the GWMME interface or the command line to migrate data from PST files.

Use the GWMME interface to migrate

Step 1: Exchange server details

  1. Run GWMME: Click Startand thenGoogle Workspace Migrationand thenGoogle Workspace Migration for Microsoft Exchange.
  2. For Server Type, select Exchange.
  3. Select the Specify a folder with PST files option.
  4. In the Folder with PST files field, specify the path to the top-level PST folder (example above).
  5. Click Next.

Step 2: User and domain information

  1. In the Google Workspace domain name field, specify the new primary Google Workspace domain where the data will be migrated.
  2. In the Service account credentials file field, specify the path to the JSON credentials file created as part of the authorization process.
  3. In the Google Workspace 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

(Option 1) To migrate directly to Google Workspace, follow these steps:

  1. Select the checkbox for each type of data you want to migrate: email, calendar, or contacts.
  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.

(Option 2) To make messages subject to Vault, but not available in users' Gmail inboxes, follow these steps:

  1. Check the Email messages box as the type of data you want to migrate.
  2. Click Advanced Options.
  3. Check the Migrate to Google Vault box and click OK.
  4. Click Next.

Step 4: Review migration settings

  1. Review the migration settings and optionally make changes.
  2. Select your migration actions:
    • Migrate all data—When checked, the utility remigrates previously migrated data during the migration. When unchecked, previous items that were migrated successfully are skipped.
    • Save settings—When checked, the utility retains 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 performs the migration.
  3. Click Next.
  4. If the authentication dialog appears, specify the username and password for the Exchange administrator account you're using to open your users' mailboxes.

    Tip: Selecting Remember my password bypasses this step in future migrations.

  5. Click Start to begin the migration process.
Use the command line to migrate

Specify the following commands to migrate using the command line. For details on commands, go to Run GWMME from the command line.

ExchangeMigration.exe --nouse_gui --pst_base_folder="PST top-level folder name" --filename="CSV file path containing user list" --service_account_json_path="json file path" --run_diagnostics


ExchangeMigration.exe --nouse_gui --pst_base_folder="C:\pst" --filename="C:\Documents and Settings\users.csv" --service_account_json_path="C:\Users\admin\privatekey.json" --run_diagnostics


  • Each example command above is a continual single line. Any line breaks visible here are for readability only.
  • If you want to make messages subject to Vault, but not available in users' Gmail inboxes, add the --migrate_to_vault argument with no parameter.
  • To avoid adding the PST file name as a prefix to labels and calendars in your destination account, add the --noenable_label_prefix argument with no parameter.


Messages missing or not migrated with the correct sender or recipient

A PST file might not contain the SMTP address for a message's sender or recipient. Instead, it can have the Exchange X.500 address. This issue can occur if no Global Address List (GAL) profile is created or the user has been removed from the GAL. To resolve the issue, go to Troubleshoot GWMME.

All calendars migrated as additional calendars

If you’re using an exported or archived PST file, it’s not possible to identify the primary root folder for Calendar and Contacts. All calendars are migrated as “additional calendars” into Google Calendar, instead of as a default calendar.

You can avoid this by using the command line to specify the --noenable_label_prefix argument with no parameter.


"C:\Program Files\Google\Google Workspace Migration\ExchangeMigration.exe" --noenable_label_prefix

Note: Running this command opens the GWMME interface allowing administrators to migrate normally, but without creating the prefixes.

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.

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