Variable: rmail-mime-prefer-html
rmail-mime-prefer-html is a customizable variable defined in
rmailmm.el.gz.
Value
t
Documentation
If non-nil, default to showing HTML part rather than text part when both are available.
This variable was added, or its default value changed, in Emacs 25.1.
Probably introduced at or before Emacs version 25.1.
Source Code
;; Defined in /usr/src/emacs/lisp/mail/rmailmm.el.gz
(defcustom rmail-mime-prefer-html
;; Default to preferring HTML parts, but only if we have a renderer
(if rmail-mime-render-html-function t nil)
"If non-nil, default to showing HTML part rather than text part
when both are available."
:group 'rmail
:version "25.1"
:type 'boolean)