Somewhere I must have tripped a switch. Normally, when opening an Inbox (incoming) or Sent items message, it's in the "Message" format, with the ribbon at the top for Reply, Forward, etc. But suddenly all messages are opening in the "File" format, which means I have to click on "Message" at the top to respond. I've looked all over and can't find a way to change this option. What did I do? Many thanks.