(define-key map "n" 'notmuch-search-next-thread)
(define-key map "r" 'notmuch-search-reply-to-thread-sender)
(define-key map "R" 'notmuch-search-reply-to-thread)
(define-key map "n" 'notmuch-search-next-thread)
(define-key map "r" 'notmuch-search-reply-to-thread-sender)
(define-key map "R" 'notmuch-search-reply-to-thread)