Platforms
- Source: Any
- Destination: Google Workspace
Problem
This error occurs when CloudM Migrate attempts to migrate an email with an attachment that is on Google's list of blocked file types. The Google Workspace Gmail API rejects the email because it does not allow the upload of these specific file types due to security restrictions.
You can view the full list of blocked file types in the Google Workspace Help Center: File types blocked in Gmail
This issue is common when migrating from non-Google platforms, but it can also occur during Google Workspace-to-Google Workspace migrations. This is typically because the emails were imported into Gmail at an earlier date, either before these file types were blocked or through a method that permitted their inclusion.
Solution
There is no direct fix for this error as it is an API-enforced limitation by Google. However, you can use the following workaround to successfully migrate the emails without their problematic attachments.
- Allow your initial migration project to complete. This will migrate all data except for the emails with the blocked attachments.
- Navigate to Items to migrate and ensure only affected users are selected to be migrated with only Mail selected.
- Navigate to Configuration > Advanced settings > Email within the CloudM Migrate platform.
-
Disable the
Migrate Attachmentssetting. - Perform a post-migration re-run.
-
Recommended: You may use the Start > Start migration for failed items
- Alternative: If the above doesn't work, you can simply restart the affected users (mail only). The Migration History feature will automatically skip already-migrated emails and only attempt to migrate the failed emails.
-
Recommended: You may use the Start > Start migration for failed items
By disabling this setting, the emails will be migrated successfully without the attachments that caused the error.