Variable: message-fill-column
message-fill-column is a customizable variable defined in
message.el.gz.
Value
72
Documentation
Column beyond which automatic line-wrapping should happen.
Local value for message buffers. If non-nil, also turn on auto-fill in message buffers.
Source Code
;; Defined in /usr/src/emacs/lisp/gnus/message.el.gz
(defcustom message-fill-column 72
"Column beyond which automatic line-wrapping should happen.
Local value for message buffers. If non-nil, also turn on
auto-fill in message buffers."
:group 'message-various
;; :link '(custom-manual "(message)Message Headers")
:type '(choice (const :tag "Don't turn on auto fill" nil)
(integer)))