Variable: message-fcc-handler-function
message-fcc-handler-function is a customizable variable defined in
message.el.gz.
Value
message-output
Documentation
A function called to save outgoing articles.
This function will be called with the name of the file to store the
article in. The default function is message-output which saves in Unix
mailbox format.
Source Code
;; Defined in /usr/src/emacs/lisp/gnus/message.el.gz
(defcustom message-fcc-handler-function #'message-output
"A function called to save outgoing articles.
This function will be called with the name of the file to store the
article in. The default function is `message-output' which saves in Unix
mailbox format."
:type '(radio (function-item message-output)
(function :tag "Other"))
:group 'message-sending)