ErrorMimeContentInvalid: The item we attempted to migrate is corrupt and was rejected by the Exchange server during migration because it has invalid MIME content.
This error message indicates the item was skipped and not migrated. In most cases, you will find that the item is not readable from the Source mailbox. If necessary, consider manually forwarding any affected items to the Destination. Alternatively, consider exporting and importing affected items using Outlook, as it may be able to correct invalid MIME content. Note that MigrationWiz tries to repair and normalize invalid MIME content, but this does not always succeed.