I'm trying to transfer all my mail to a new Macbook pro. I was told the way to do this is to replace the entire Mail folder in the user library with the one from the old computer. The message headers are all in my inbox now, but when I select a message, the message body reads "The message from louisa <firstname.lastname@example.org> concerning New arrangement for brainstorming session has not been downloaded from the server. You need to take this account online in order to download it. The messages in other folders display fine. Anyone know what the problem is and how to resolve it?