I've become rather fond of Markdown and think it would be rather well suited to emails.
How do I set up Gmail to allow me to format reading and sending emails in Markdown? Is this even possible?
If the worst comes to the worst, I'd be open to another email service that offered a Markdown editor. One that will also parse Markdown formatted (which often look like plain-text) emails.
Best Answer
I've created a Chrome, Firefox, and Thunderbird extension that allows you to write email in Markdown (in Gmail, Yahoo, Hotmail, or Thunderbird) and then convert to HTML before sending.
If someone sends you raw Markdown it won't render it for you, but it lets you send rendered Markdown to others.
Hope it helps.
https://github.com/adam-p/markdown-here