Emacs/GNUs biff display-time-mode not updating mail

Question

I recently made the switch from OpenSUSE 12.2/KDE to Fedora 19/Gnome; my .emacs has stayed the same. In particular, I am using (display-time-mode 1) On KDE, this worked beautifully to provide me a "mail" update whenever my Fetchmail daemon grabbed new messages. However, now on Gnome, I only get a biff notification when I have just started emacs, or when I re-evaluate my .emacs file. I have tried this in both emacs and emacsclient, and neither seems to automatically provide biff anymore; I'm not sure what's changed (emacs version is probably different, but why would a newer version break this?). Help, please!

Pertinent code from .emacs:

;; Clock & Biff display
(setq display-time-24hr-format t)
 ;; display-time-mode mail notification
(defface display-time-mail-face '((t (:background "red")))
  "If display-time-use-mail-icon is non-nil, its background colour is that
      of this face. Should be distinct from mode-line. Note that this does not seem
      to affect display-time-mail-string as claimed.")
(setq
 display-time-mail-file "/var/mail/torys"
 display-time-use-mail-icon t
 display-time-mail-face 'display-time-mail-face)
(display-time-mode 1)

GNU Emacs 24.3.1 (x86_64-redhat-linux-gnu, GTK+ Version 3.8.2) of 2013-08-14 on buildvm-15.phx2.fedoraproject.org

Answer 1

Tripleee was correct: although I had fixed most of the paths across my .gnus and .fetchmailrc, I had missed these crucial lines:

nnmail-spool-file "/var/mail/[my user]"
display-time-mail-file "/var/mail/[my user]"

Obviously, those are the key lines for getting it to work properly.