Function: message-insert-header
message-insert-header is a byte-compiled function defined in
message.el.gz.
Signature
(message-insert-header HEADER VALUE)
Source Code
;; Defined in /usr/src/emacs/lisp/gnus/message.el.gz
(defun message-insert-header (header value)
(insert (capitalize (symbol-name header))
": "
(if (consp value) (car value) value)))