(message-options-set, message-narrow-to-head)

(message-options-set, message-narrow-to-head)
(message-in-body-p, message-mail-p, message-encode-message-body): Autoload.
(message-remove-header, message-narrow-to-headers-or-head)
(message-subscribed-p, message-make-mail-followup-to)
(message-position-on-field, message-news-p)
(message-options-set-recipient, message-generate-headers)
(message-sort-headers): Declare as functions.