Adds keyboard shortcuts to change folder, move/copy messages, with folder name auto-completion (using only the keyboard). Same for tags. Also includes a system of rules to suggest a target folder for saving messages; re-creates Eudora's Alt-Click; facilitates navigation in the 3-pane window; makes it easy to change between To/Bcc/Cc fields in the composer; facilitates tag-oriented operations. All that with the keyboard only!