C-c C-y message-yank-original (insert current message, if any).
C-c C-q message-fill-yanked-message (fill what was yanked).
C-c C-e message-elide-region (elide the text between point and mark).
+C-c C-z message-kill-to-signature (kill the text up to the signature).
C-c C-r message-caesar-buffer-body (rot13 the message body)."
(interactive)
(kill-all-local-variables)