When I was moving a mailbox from Exchange 2007 to Exchange 2010 I had mailbox moves which fail due to the “corrupt” limit being hit.

errorMessage: Message (size 11.00 MB ) exceeds the maximum allowed size for submission to the target mailbox. You can increase this limit by using the Set-Mailbox cmdlet in the Exchange Management Shell.

And while this can be fixed by doing the following:
Go to to user mailbox properties (in EX2010), then go to mail flow settings, then set Message Size Restriction properties and set both Sending and Receive message size to high value (99999).

Then go Move Request node again and resume the move request and it should work. Just remember to go back to the user mailbox setting again and set Message size restriction to its default value.

This is a per mailbox solution and doesn’t scale when moving many email boxes over in the migration process.

So before attempting any mailbox moves during a migration from 2007 to 2010, make sure you set the send receive limit to something larger, otherwise valid messages will be dropped as “corrupt” messages simply because they are over the size limit

Set the limit under global config -> hub transport -> global setting

– jermal