Variable: message-user-fqdn
message-user-fqdn is a customizable variable defined in message.el.gz.
Value
nil
Documentation
Domain part of Message-IDs.
This variable was added, or its default value changed, in Emacs 22.1.
Probably introduced at or before Emacs version 25.1.
Source Code
;; Defined in /usr/src/emacs/lisp/gnus/message.el.gz
(defcustom message-user-fqdn nil
"Domain part of Message-IDs."
:version "22.1"
:group 'message-headers
:link '(custom-manual "(message)News Headers")
:type '(radio (const :format "%v " nil)
(string :format "FQDN: %v")))