Variable: mail-yank-prefix
mail-yank-prefix is a customizable variable defined in sendmail.el.gz.
Value
"> "
Documentation
Prefix insert on lines of yanked message being replied to.
If this is nil, use indentation, as specified by mail-indentation-spaces.
Probably introduced at or before Emacs version 19.1.
Source Code
;; Defined in /usr/src/emacs/lisp/mail/sendmail.el.gz
;;;###autoload
(defcustom mail-yank-prefix "> "
"Prefix insert on lines of yanked message being replied to.
If this is nil, use indentation, as specified by `mail-indentation-spaces'."
:type '(choice (const nil) string))