Troubleshoot an Exchange connection

To troubleshoot your Exchange connection, make sure you: 

• Meet all the system requirements for Exchange.

  For details, go to Exchange requirements.

• Have the correct Exchange administrator credentials. If the credentials changed, enter the new credentials and try again.
• Use a third-party tool like EWSEditor to check if you can connect to your Exchange server from all servers running Google Workspace Migrate.
  
  Note: Google Workspace Migrate uses the same Exchange Web Services (EWS) connection method as EWSEditor. If the tool fails to connect, Google Workspace Migrate will not successfully connect. Work with your Exchange admin to resolve these connection issues.
  
  Third-party tools are not supported by Google. Problems with a third-party tool must be handled by the third-party vendor.

To complete basic user validation, make sure the user account:

• Exists in Exchange and in Google Workspace.
• Is not frozen, suspended, or renamed.

If you try to add an Exchange Online (Microsoft 365) connection, you might get a Could not access searchable mailboxes: The caller has not assigned any of the RBAC roles requested in the management role header error.

The error is due to delays by Exchange in processing new administrator permissions. Wait for the permissions to propagate in Exchange and try again.

If you use email forwarding and the Accelerate Old Messages setting is turned on, set the Insert Before Date field to one day before email forwarding was turned on. Google Workspace Migrate uses this date to check that incoming email messages don’t already exist in the target mailbox.

For details on how to copy Exchange content using the Accelerate Old Messages setting, go to About Exchange settings template options.

If your Exchange server uses complex filters, you might not see certain filters and actions migrated into Google Workspace. Not all Exchange actions and conditions map to a Gmail equivalent.

For a list of the Exchange filters that are not migrated, go to Monitoring points for Exchange.

Following a migration, you might notice that the number of email messages in the source environment exceeds the number of messages migrated to Gmail. 

This discrepancy might be due to the difference between folders in Exchange and labels in Gmail. In Exchange, when you assign a message to more than one folder, the message is duplicated. Following a migration, the duplications are removed in Gmail and different labels are applied instead. 

To verify that all messages have been migrated, check the logs for any errors. For details, go to Monitor migration progress.

If you think you’re missing some messages, make sure: 

• The message, including attachments, is not bigger than 25 MB. You can’t migrate messages bigger than 25 MB. For details, go to Send attachments with your Gmail message.
• An attachment to the message is not blocked by Gmail. Gmail blocks certain types of attachments, such as executable files. For details, go to File types blocked in Gmail.
• The message is in a folder or within a date range that’s part of the migration.

Both Exchange and Gmail allow users to delegate access to their email. However, Google Workspace Migrate doesn’t migrate delegation settings from Exchange. If you want to delegate access, you need to turn on mail delegation in Gmail after a migration. 

Important notes about Gmail delegation

• Gmail doesn’t support folder level or read-only delegate access.
• Each Gmail account has a maximum of 1,000 delegates.
• The delegate must be an individual user, not a group in Google Groups.
• Calendar permissions are managed separately from Gmail permissions.

Step 1: (Optional) Export delegate information from Exchange

To export the delegate permissions from Exchange, in PowerShell choose an option: 

• To extract mailbox delegation permissions (full access to a user's mailbox), use Get-MailboxPermission. 
• To extract folder sharing permissions (access to user's mail folders), use Get-MailboxFolderPermission. 

Step 2: Turn on mail delegation in the Admin console

Before your users can delegate access to their mailboxes, you need to turn on a setting in the Google Admin console. For details, go to Turn Gmail delegation on or off.

Tip: You can limit who can set up mail delegation by adding those users to an organizational unit. 

Step 3: Set up mail delegation for users

Choose an option:

• Have your users set up delegation in Gmail. For details, go to Delegate and collaborate on email. 
• Use the Gmail API to set up delegation for multiple users at the same time. For details, go to Managing Delegates. 

Tip: You can use an open source tool to script Gmail API settings changes. For details, go to ExamplesEmailSettings.

Other options

In Gmail, you can send messages from an address belonging to another user or group in Google Groups without granting mailbox access. For details, go to Send emails from a different address or alias. You can also use the Gmail API to control this setting. 

Related topics

See these Microsoft articles for information on delegate access:

• Manage another person's mail and calendar items
• Manage permissions for recipients
• Manage permissions for recipients in Exchange Online

If you see a 400 error relating to Exchange calendars, make sure the original event organizer was not removed from Exchange. If they were, use the settings template for Exchange to assign a default email address and to set a suffix in the calendar event to reset the organizer.

For details, go to Set up or select a settings template.