There's now an Archive menu item as well as a corresponding toolbar button. This creates a folder "Archive" if it doesn't exist and moves the items there. I can't seem to find a way to set which folder the "Archive" button moves the mail to though. Is this hard coded? or has anyone found a way to set this? I'm guessing there should be a menu option: Mailbox -> Use this Mailbox for -> Archive, but there isn't.