Hi ParvinderRandev3513,
Given the situation, I would like to collect some logs for analysis.
We can view the details in the right part of the migration batch page, and select the one of the failed user mailbox.
Then you can use Exchange Online PowerShell to run the following cmdlet.
Get-MigrationUserStatistics -Identity *** Email address is removed for privacy *** -IncludeReport | FL
I have sent a private message to you to request the output. In addition, I suggest you check this mailbox on Office 365 side and confirm whether all email data has been migrated successfully. What if you remove the batch, and recreate a new one?
To see the private message, please perform the following steps:
- Please go to "Your details" section on the right side of the community site.
- Click Private messages.
- Click the subject title (request information) of the response to read the message.
Thanks,
Johnny Zhang