+(defcustom message-wide-reply-confirm-recipients nil
+ "Whether to confirm a wide reply to multiple email recipients.
+If this variable is nil, don't ask whether to reply to all recipients.
+If this variable is non-nil, pose the question \"Reply to all
+recipients?\" before a wide reply to multiple recipients. If the user
+answers yes, reply to all recipients as usual. If the user answers
+no, only reply back to the author."
+ :group 'message-headers
+ :type 'boolean)
+