Do the global key bindings only via loaddefs.el,

not when sendmail.el is loaded.

lisp/mail/sendmail.el

@@ -831,16 +831,11 @@ The seventh argument ACTIONS is a list of actions to take
     (pop-to-buffer "*mail*"))
   (mail noerase to subject in-reply-to cc replybuffer sendactions))
 
-
-;;;###autoload
-(define-key ctl-x-map "m" 'mail)
-
-;;;###autoload
-(define-key ctl-x-4-map "m" 'mail-other-window)
-
-;;;###autoload
-(define-key ctl-x-5-map "m" 'mail-other-frame)
-
+;;; Do not execute these when sendmail.el is loaded,
+;;; only in loaddefs.el.
+;;;###autoload (define-key ctl-x-map "m" 'mail)
+;;;###autoload (define-key ctl-x-4-map "m" 'mail-other-window)
+;;;###autoload (define-key ctl-x-5-map "m" 'mail-other-frame)
 
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