Variable: message-forward-included-mime-headers
message-forward-included-mime-headers is a customizable variable
defined in message.el.gz.
Value
("^Content-Type:" "^MIME-Version:")
Documentation
When forwarding as MIME, but not using MML, don't delete these headers.
Also see message-forward-ignored-headers and
message-forward-ignored-headers.
When forwarding messages as MIME, but when
message-forward-show-mml results in MML not being used,
message-forward-included-mime-headers take precedence.
This variable was added, or its default value changed, in Emacs 28.1.
Probably introduced at or before Emacs version 28.1.
Source Code
;; Defined in /usr/src/emacs/lisp/gnus/message.el.gz
(defcustom message-forward-included-mime-headers
'("^Content-Type:" "^MIME-Version:")
"When forwarding as MIME, but not using MML, don't delete these headers.
Also see `message-forward-ignored-headers' and
`message-forward-ignored-headers'.
When forwarding messages as MIME, but when
`message-forward-show-mml' results in MML not being used,
`message-forward-included-mime-headers' take precedence."
:version "28.1"
:group 'message-forwarding
:type '(repeat :value-to-internal (lambda (widget value)
(custom-split-regexp-maybe value))
:match (lambda (widget value)
(or (stringp value)
(widget-editable-list-match widget value)))
regexp))