Troubleshoot the data migration service

You might see 2 types of migration problems when using the data migration service—blocking or non-blocking issues.

Blocking issues

Blocking issues prevent the migration of user accounts. They usually occur if you enter an incorrect username or password when you set up migrations from IMAP environments. Or, you might see them if your Microsoft® Exchange administrator account lacks certain privileges.

Non-blocking issues

Non-blocking issues prevent some, but not all, messages from migrating. You might see message-level errors (where a single message hasn't migrated correctly) or folder-level errors (where an entire folder hasn't migrated).

Address blocking issues

Migrating from an Exchange Web Services environment (Exchange 2007 and later)

If you encounter problems when migrating from a Microsoft Exchange Web Services (EWS) environment, verify:

  1. EWS—Select the Synchronization, Notification, Availability, and Automatic Replies option in the Microsoft Remote Connectivity Analyzer to verify that servers can reach and, through autodiscovery, recognize EWS.
  2. The logs show that the data migration service can communicate with Exchange—Check the Exchange server Internet Information Services (IIS) logs to see if you get the SyncFolderItems call with response code 200.
  3. Impersonation—Check the following Microsoft links to verify impersonation information for:
  4. TLS certificates—Verify that your TLS certificates are signed and valid. For details, see Set up your TLS certificate.
  5. Exchange user account—Verify that the Exchange user account is a valid account and the mailbox enabled. Also, check that the Exchange mailbox isn't corrupt.
  6. Migration client ID—Verify that the following client ID appears in the list of clients that have access to mail and migration APIs:

    955661971872-ie97v0ns6ndb19rbr9nlpkahpmfk9ugf.apps.googleusercontent.com

    To check the client ID:

    1. From the Admin console dashboard, click Security and then Advanced settings
    2. Under Authentication, click Manage API client access

      You should see the client ID listed under Authorized API clients.

    If the client ID doesn't appear:

    1. In the Client name field, copy and paste the client ID. 
    2. In the One or more API scopes field, copy and paste the following scopes: https://mail.google.com/, https://www.googleapis.com/auth/email.migration, https://www.googleapis.com/auth/gmail.insert, https://www.googleapis.com/auth/gmail.labels
    3. Click Authorize
  7. The relevant Google service—Check that you turned on the target Google service (Gmail, Contacts, or Calendar). For details, see Control who can access Google services
  8. The super administrator—Check that a super administrator is assigned to the G Suite domain.
  9. Your server gets connections from G Suite mail servers—For details, see Google IP address ranges for outbound SMTP.
Migrating from IMAP, Gmail, or a G Suite account

Blocking issues when migrating from an IMAP server, Gmail, or a G Suite account might indicate an obstacle accessing the mailbox. Try to access the mailbox using an IMAP email client such as Thunderbird®, Apple® Mail, or Microsoft Outlook®. This ensures the mailbox has IMAP access and that you have the correct username and password.

If you still see issues, verify the following:

  1. Migration client ID—Verify that the following client ID appears in the list of clients that have access to mail and migration APIs:

    955661971872-ie97v0ns6ndb19rbr9nlpkahpmfk9ugf.apps.googleusercontent.com

    To check the client ID:

    1. From the Admin console dashboard, click Security and then Advanced settings
    2. Under Authentication, click Manage API client access.

      You should see the client ID listed under Authorized API clients.

    If the client ID doesn't appear:

    1. In the Client name field, copy and paste the client ID. 
    2. In the One or more API scopes field, copy and paste the following scopes: https://mail.google.com/, https://www.googleapis.com/auth/email.migration, https://www.googleapis.com/auth/gmail.insert, https://www.googleapis.com/auth/gmail.labels
    3. Click Authorize
  2. The relevant Google service—Check that you turned on the target Google service (Gmail, Contacts, or Calendar). For details, see Control who can access Google services
  3. The super administrator—Check that a super administrator is assigned to the G Suite domain.
  4. Your server gets connections from G Suite mail servers—For details, see Google IP address ranges for outbound SMTP.

Address non-blocking issues

If non-blocking issues or errors occur, request a domain migration and item error report. See How to monitor a migration for detail on migration reports. Then, try troubleshooting non-blocking issues. 

Troubleshoot missing messages

Step 1: Check your set up steps

If you have a blocking issue, check that you completed all the steps to set up your legacy environment and retry the migration. Then, if the problem persists, try troubleshooting blocking issues.

Step 2: Check for the email header

If some email messages seem to disappear after a migration, perform the following search to make sure the email isn't simply mislabeled:

  1. Get the message-id header of the email from the legacy account.
  2. Search for the header in the new G Suite account using the rfc822msgid: Gmail search operator. For details, see Search operators you can use with Gmail.

Step 3: Additional checks

If you still can't find the email, perform the following checks:

Troubleshoot missing email folders

If you have an email folder that is missing after a migration, contact your legacy email service provider to see whether they can resolve the issue with the folder. 

If the issue can’t be resolved, you could delete the folder and run the migration again. Any email messages contained within the folder would also be deleted, however.

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