"variable [in .emacs] is void"

[gebser]

When starting emacs, an error is reported in *Messages*:

Error in init file: Symbol's value as variable is void: mail-mode-map

The first place in .emacs where that variable occurs is:

(add-hook 'mail-setup-hook
          '(lambda ()
             (substitute-key-definition
               'next-line 'mail-abbrev-next-line
               mail-mode-map global-map)
             (substitute-key-definition
               'end-of-buffer 'mail-abbrev-end-of-buffer
               mail-mode-map global-map)))

My guess is that some other code is required prior to this.  After emacs 
is loaded and I do "M-x mail", I can evaluate it fine (in .emacs).  

Any ideas?


tnx,
ken