rmail. emacs. How to set a chime. How to list headers before hitting g.

[Don Saklad]

a. In rmail in emacs, how would you set a little chime or bell signal
   that more email arrived since the last time you checked rmail ?...


b. In rmail in emacs, how would you set up something that would list
   headers of pending email before you have even pressed the letter g
   key for checking rmail messages?...