Troubleshoot Exchange Online data migrations

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Here's how to fix problems you might have with a Microsoft Exchange Online migration.

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Can't start a migration

If you get an error when you try to start a migration, make sure that a Google Workspace user with super administrator privileges sets up and initiates the migration.

Need permission to access resources error

If you get a Needs permission to access resources in your organization that only an admin can grant error, make sure that you're trying to connect to the Microsoft account using a valid Global Administrator account. For details, go to Connect to your Microsoft account.

User account issues

Before you begin a migration, you have to set up the user accounts in Google Workspace. For details on setting up user accounts, go to Options for adding users.

A user account that is not set up, or set up incorrectly, can cause the following issues in the reports.

Report message

How to fix

User not found

Mail service not enabled for source user

The source email address is invalid
  • Confirm that the Microsoft Exchange Online source account in your list of source users is correct.
  • Confirm the Microsoft Exchange Online source account in your identity map is correct.
  • Confirm that you chose to copy user addresses that aren't found in the list you uploaded.
  • Ensure that the source user has the correct licenses assigned in Microsoft and is able to access their mailbox.
Google Calendar Service is disabled for the target user Turn on the Calendar service for your users. For details, go to Turn Calendar on or off for users.

For other errors with the new data migration service, go to general troubleshooting help.

Error uploading migration maps

When you upload your migration or identity map, you might get one of the following errors at the bottom or next to Tasks .

Error message

Steps to troubleshoot

Internal error occurred while adding this entry

Invalid CSV file

Confirm that the CSV headers are correct. For details, go to Create a list of users to transfer.

Source Entry is already mapped

A source email address was added more than once in your identity map. Check for duplicate source users.

Note that target users can be listed more than once.

Entry already exists

A source email address was added more than once in your migration map. Check for duplicate source users.

Source and target identity for all entries must be valid email

Confirm all email addresses are the correct format (example: user@example.com).

Migration fails to start

Make sure that a target domain super admin starts the migration. The new data migration service requires super admin privileges as it grants domain-wide delegation in the target domain before it begins to migrate data.

Migration completes, but there are failed items

Click Export migration report and use the report to identify items that didn't migrate and why. For details, go to Understand Exchange Online data migration reports.

Once you identify the issues, run a delta migration.

Error migrating folders

Sometimes messages present in a folder migrate in a warning state. They will not have the label that corresponds to their folder attached.

To troubleshoot, try running a delta migration. If the issue persists, you can:

Then, run a delta migration again.


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