Are you moving databases from Exchange X to Exchange 2010 and receiving below warning ? if yes you need to check AcceptLargeDataLoss out in Exchange 2010.
The AcceptLargeDataLoss parameter specifies that a large amount of data loss is acceptable if the BadItemLimit is set to 51 or higher. Items are considered corrupted if the item can't be read from the source database or can't be written to the target database. Corrupted items won't be available in the destination mailbox
Replace the mail address to your own…… and run this from PS on your Exchange 2010 server. You can change the acceptable corrupted item number as you wish…
New-MoveRequest -Identity 'firstname.lastname@example.org' -TargetDatabase "DB10" -BadItemLimit 10000 -AcceptLargeDataLoss