   (add-to-list 'mu4e-view-actions
                '("bView in browser" . mu4e-action-view-in-browser) t)
   ;; search for messages by the sender of the opened message
-  (defun search-for-sender (msg)
+  (defun my/search-for-sender (msg)
     "Search for messages sent by the sender of the message at point."
     (mu4e-headers-search
     (concat "from:" (cdar (mu4e-message-field msg :from)))))
   (add-to-list 'mu4e-view-actions
-               '("xSearch for sender" . search-for-sender) t)
+               '("xSearch for sender" . my/search-for-sender) t)
 
   ;; set `mu4e' as emacs' default email program
   (setq mail-user-agent 'mu4e-user-agent)

;;
;; Aaron LI
;; Created: 2016-02-21
;; Updated: 2016-09-03
;;

;;; Commentary:

  ;; compose messages in a separate frame
  (setq mu4e-compose-in-new-frame t)

  ;; customize the reply/quote citation format
  (setq message-citation-line-format "On %a, %b %d, %Y at %R, %f wrote:\n")
  ;; choose to use the above formatted string
  (setq message-citation-line-function 'message-insert-formatted-citation-line)

  ;; confirm before sending
  (add-hook 'message-send-hook
            (lambda ()
