I avoid that by replying inline, discarding the history of multiple-quoted emails from top-repliers. Everybody else uses Outlook, but nobody has yet complained.

For sending emails with formatting (italics, headings), I use Markdown in Vim then press H in Mutt before sending, which pipes it through an appropriate filter:

set send_multipart_alternative_filter=html_alternative send-hook . 'set send_multipart_alternative=no' macro compose H ':set send_multipart_alternative=yes<Enter><view-alt-mailcap>' 'add HTML alternative'