Username or EmailPassword
You can drag folders to the root level in mail.app. But its done badly, if you drag to a space between two other folders at root level it will highlight a position (based on alphabetic order) in the root level. I've moved folders and sub-folders around. But like I said its done badly, the logical thing would be to drag the folder to the "On My Mac" line.
That's Tiger behaviour. In Leopard that's no longer possible.
My leopard install begs to differ :0)
Tested when I saw the cartoon and tested it again now. It works fine!