Variable: rmail-preserve-inbox
rmail-preserve-inbox is a customizable variable defined in
rmail.el.gz.
Value
nil
Documentation
Non-nil means leave incoming mail in the user's inbox--don't delete it.
Source Code
;; Defined in /usr/src/emacs/lisp/mail/rmail.el.gz
(defcustom rmail-preserve-inbox nil
"Non-nil means leave incoming mail in the user's inbox--don't delete it."
:type 'boolean
:group 'rmail-retrieve)