Commonmark in emails

The text/markdown content type is specified in RFCs 7763 and 7764. Commonmark is declared as text/markdown; variant=CommonMark.

I was curious whether it could transparently replace text/plain in email communication, but apparently several clients do not fall back gracefully to text/plain although they ought to.

I also tried to find email clients that not only support entering markdown (and convert to HTML), but also announce it somehow in the Content-Type header for the plain text part. The few I found use text/plain; markup=markdown instead.

Should users petition app makers to support either the subtype or the parameter?


Native support in both MUAs and browsers seem like an important goal.


Hi all!

  1. I don’t know if you know, but there is a new email protocol as an alternative to smtp that uses commonmark specification for files email - here:
  2. I don’t know if it’s a secure protocol, but I found it interesting how the topic here is to use commonmark in emails… I thought I’d add about it here

"As well as letting sites reach customers/members directly & securely, TMTP also benefits end users:

It provides a far safer model than email, where you:
 + choose the sites where you participate 
 + select which members of a site can message you
 + always know from which site a message originated
 + can block anyone with whom you’ve made contact
 + may leave a site and never see traffic from it again

It offers capabilities missing in email, including:
 + message formatting & layout via Markdown (aka CommonMark)
 + hyperlinks to messages and other threads
 + hashtags and private tags
 + slide deck layouts
 + data-driven charts & graphs
 + forms/surveys whose results are collected into tables
 + many more features to foster focus, creativity, efficiency, and clarity