The following small snippet of emacs-lisp creates an asynch process via
popclient (by Carl Harris) to allow POP3 auth.  I have a synchronous
(open-network-stream) emacs-lisp function in the works for people who don't
have popclient available, unfortunately I don't have any specifications for
the POP3 protocal, so I've just been emulating popclient's reactions.

A couple notes:  Yes, I copied ange-ftp's password function (I still think
a password function should be a intrinsic byte-compiled emacs function
which "secures" the X server) since I'm going to add a secure to the
function.  I'm still trying to decipher's ange-ftp's ability to cache the
password while keeping it "directly" unreadable.

For an example I have as my retrieve-error-hook

(add-hook 'retrieve-error-hook	'retrieve-message-error)

(defun retrieve-message-error ()
  (message "Houston, we have a problem.")
  (wav-fx-play "houston.wav" 0.5))