Some users’ mailbox migrations from Google to Exchange Online did not complete as expected

Title: Some users’ mailbox migrations from Google to Exchange Online did not complete as expected

User impact: Users’ mailbox migrations from Google to Exchange Online did not complete as expected.

More info: Migrations that were initiated using Microsoft’s data migration tool were affected. Users who completed their migrations would have observed that Deleted, Archive, and Junk mailboxes had shown a difference in size after the migration.

Instructions to resume or restart the affected migrations:

For any Google onboarding migration that was completed between March 7, 2024, and April 20, 2024, please re-initiate the onboarding migration with the below options:

– IncludeFolders “#Archive#”,”#DeletedItems#”,”#JunkEmail#”
– SkipRules -SkipCalendar -SkipContacts -SkipDelegates

For any Google onboarding that was created before April 20, 2024, but the migration was not completed or removed, please take the following action:

– Remove the migration user/batch and inject a new migration batch but do not use “include folders” and “skip options” so that all folders are synced properly.

Current status: The deployment of the fix has successfully been completed and users can resume their scheduled migrations. For instructions on how to restart migrations that were initiated between March 7, 2024, and April 20, 2024, please see the “More info” section of this communication.

Scope of impact: Any user who was attempting to migrate from Google to Exchange Online using Microsoft’s data migration tool was impacted.

Start time: Thursday, March 7, 2024, at 12:00 AM UTC

End time: Saturday, April 20, 2024, at 12:00 PM UTC

Root cause: A code issue was introduced in a recent service update which was preventing migrations from Google to Exchange Online using Microsoft’s data migration tool from completing as expected, specifically, the mailbox items with the Deleted, Archive, or Junk labels were not migrated.

This is the final update for this event.