rmail-speedbar-menu-items

rmail-speedbar-menu-items is a variable defined in `rmail.el'.
Its value is

(["Read Folder" speedbar-edit-line t]
 ["Move message to folder" rmail-speedbar-move-message-to-folder-on-line
  (save-excursion
    (beginning-of-line)
    (looking-at " "))])

Documentation:
Additional menu-items to add to speedbar frame.