I write all my emails in plain text, not rich text or HTML, but I do use punctuation markup as has been popularized by Markdown and others (which were inspired by prior customs in plain-text email). There’s RFC 7763 now, which registers the text/markdown media type with mandatory charset and optional variant parameters. Can I change Apple Mail to always send a respective MIME header?

Content-Type: text/markdown; charset=UTF-8; variant=pandoc; extensions=-raw_html

I hope for some defaults write magic since there doesn’t seem to be a respective plugin available (yet). Something like this:

defaults write com.apple.mail UserHeaders \
  '{"Content-Type: text/markdown; charset=UTF-8; variant=pandoc; extensions=-raw_html"; }'
  • 2
    Are you aware of any mail client which does this already? Or any mail client which renders rich text when it receives a message with such a header? Jun 19, 2016 at 17:30
  • @TomGewecke Not really. MailMate and Groups.io support Content-Type: text/plain; markup=markdown", though, which would need the same kind of hackery in Mail.app. I’ve filed a feature request to Apple and will do so for Thunderbird.
    – Crissov
    Jun 20, 2016 at 12:58
  • Also see superuser.com/questions/1361551/using-text-markdown-in-emails for why this, unfortunately, might not be such a great idea after all.
    – Crissov
    Sep 29, 2018 at 22:02

1 Answer 1


Would Brett Terpstra’s Markdown Service Tools provide what you need? Here's a nice blog-post explaining how to it up and running, also en Mail.

  • No, not at all. These macros are helful for writing and converting Markdown, but do nothing to alter the format Mail is using.
    – Crissov
    Feb 5, 2017 at 14:36
  • My bad. Guess I misunderstood your question.
    – Eric Fail
    Feb 5, 2017 at 20:01

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