Set revert-buffer-function in the right place

mu4e/mu4e-main.el

@@ -66,7 +66,9 @@
   (use-local-map mu4e-main-mode-map)
   (setq
     truncate-lines t
-    overwrite-mode 'overwrite-mode-binary))
+    overwrite-mode 'overwrite-mode-binary
+    (setq revert-buffer-function 'mu4e:main-revert-buffer)
+    ))
 
 
 (defun mu4e~main-action-str (str &optional func-or-shortcut)
@@ -153,8 +155,6 @@ clicked."
 	(mu4e~main-action-str "\t* [q]uit\n" 'mu4e-quit))
       )))
 
-(setq revert-buffer-function 'mu4e:main-revert-buffer)
-
 ;; NEW
 ;; Revert mu main buffer then switch to it
 (defun mu4e~main-view ()