(define-key map " " 'notmuch-tree-scroll-or-next)
(define-key map (kbd "DEL") 'notmuch-tree-scroll-message-window-back)
(define-key map "e" 'notmuch-tree-resume-message)
(define-key map " " 'notmuch-tree-scroll-or-next)
(define-key map (kbd "DEL") 'notmuch-tree-scroll-message-window-back)
(define-key map "e" 'notmuch-tree-resume-message)