11.6 How can I force Rmail to reply to the sender of a message, but not the other recipients?

Ron Isaacson says: When you hit r to reply in Rmail, by default it Ccs all of the original recipients (everyone on the original ‘To’ and ‘CC’ lists). With a prefix argument (i.e., typing C-u before r), it replies only to the sender. However, going through the whole C-u business every time you want to reply is a pain. This is the best fix I’ve been able to come up with:

(defun rmail-reply-t ()
  "Reply only to the sender of the current message. (See rmail-reply.)"
  (interactive)
  (rmail-reply t))

(add-hook 'rmail-mode-hook
  (lambda ()
    (define-key rmail-mode-map "r" 'rmail-reply-t)
    (define-key rmail-mode-map "R" 'rmail-reply)))