Sample error message: Unable to decode message …. Encountered exception – Internal Mime error: Single text value size (32798) exceeded allowed maximum (32768)
Explanation
Google Gmail and Microsoft Exchange utilize different underlying mail protocols. As such, edge cases may arise during the migration where an error would occur because of these differences.
An example of this error is the sample error listed above, which indicates that the header content of the email is too large to be migrated into Microsoft Exchange. A typical supported email header size is 32KB. Other variations of this error may occur.
This is a limitation caused by the protocols and there is currently no workaround at this moment.