with plugged status instead of `'force' as 2nd argument.
 
        * wl-summary.el (wl-summary-refile-subr): Cause an error if FOLDER
        is not writable.
+       (wl-summary-sync-update): Call `wl-folder-confirm-existence' with
+       plugged status instead of `'force' as 2nd argument.
 
        * wl-folder.el (wl-folder-create-subr): Cause an error if FOLDER
        is not creatable.
 
          ;;(setq seen-list
          ;;(wl-summary-flush-pending-append-operations seen-list))
          (goto-char (point-max))
-         (wl-folder-confirm-existence folder 'force)
+         (wl-folder-confirm-existence folder (elmo-folder-plugged-p folder))
          (setq sync-result (elmo-folder-synchronize
                             folder
                             wl-summary-new-mark