(re-search-forward notmuch-show-header-end-regexp)
(overlay-put (make-overlay beg (match-beginning 0))
'invisible 'notmuch-show-header)))
(re-search-forward notmuch-show-header-end-regexp)
(overlay-put (make-overlay beg (match-beginning 0))
'invisible 'notmuch-show-header)))