While performing Migration of mailboxes from Exchange 2003 to Office 365, mailbox move fails because of Bad Item Exceeds the limit of 100 set by us. we then take permission from authorities to increase the limit before retrying it.
we want to know is there any way to check the bad item count in mailbox before starting the migration. that will be of great help.
Exchange doesn't know, in advance, how many "bad items" there are; it counts them during the move. So the only way you'd know is to try migrating the items, and see which ones Exchange ran into problems with.
Further, Exchange Server 2003 doesn't support PowerShell directly.