Variable: message-generate-headers-first
message-generate-headers-first is a customizable variable defined in
message.el.gz.
Value
nil
Documentation
Which headers should be generated before starting to compose a message.
If t, generate all required headers. This can also be a list of headers to
generate. The variables message-required-news-headers and
message-required-mail-headers specify which headers to generate.
Note that the variable message-deletable-headers specifies headers which
are to be deleted and then re-generated before sending, so this variable
will not have a visible effect for those headers.
Source Code
;; Defined in /usr/src/emacs/lisp/gnus/message.el.gz
(defcustom message-generate-headers-first nil
"Which headers should be generated before starting to compose a message.
If t, generate all required headers. This can also be a list of headers to
generate. The variables `message-required-news-headers' and
`message-required-mail-headers' specify which headers to generate.
Note that the variable `message-deletable-headers' specifies headers which
are to be deleted and then re-generated before sending, so this variable
will not have a visible effect for those headers."
:group 'message-headers
:link '(custom-manual "(message)Message Headers")
:type '(choice (const :tag "None" nil)
(const :tag "All" t)
(repeat (sexp :tag "Header"))))