The maximum number of corrupted items a move request will allow you to enter in the GUI for skipping is 50. If you enter more it will act like it will work then not do the move.
If a mailbox move fails with too many errors you will need to move the mailbox via an exchange PowerShell command line (make sure you run the exchange PowerShell not the general PowerShell). The command line is as follows:
New-MoveRequest -Identity <USERNAME> -AcceptLargeDataLoss -BadItemLimit ‘<max number of corrupted items>’ –TargetDatabase <GUID>
You can get your database GUID’s with this command:
Get-MailboxDatabase | fl Identity, GUID
So for example to move testuser to a database with GUID 89261a9a-ce53-41bb-a652-1361bc3616e0 and allow up to 999 corrupted items you would use the following command:
New-MoveRequest -Identity testuser -AcceptLargeDataLoss -BadItemLimit ‘999’ -TargetDatabase 89261a9a-ce53-41bb-a652-1361bc3616e0