Variable: message-user-path
message-user-path is a customizable variable defined in message.el.gz.
Value
nil
Documentation
If nil, use the NNTP server name in the Path header.
If stringp, use this; if non-nil, use no host name (user name only).
Source Code
;; Defined in /usr/src/emacs/lisp/gnus/message.el.gz
(defcustom message-user-path nil
"If nil, use the NNTP server name in the Path header.
If stringp, use this; if non-nil, use no host name (user name only)."
:group 'message-news
:group 'message-headers
:link '(custom-manual "(message)News Headers")
:type '(choice (const :tag "nntp" nil)
(string :tag "name")
(sexp :tag "none" :format "%t" t)))