I'm chatting with my nanobot using email. The replies are nicely formatted in Markdown. But email clients don't by default render Markdown. Adding "Render Markdown Messages" to Thunderbird enables pretty output.
The problem is that if the add-on is applied to all messages, plain text is messed up. Opting to be selective stops the nice rendering of nanobot messages.
What I am seeing in the content type header is: text/plain; charset=UTF-8. It would be really helpful if it could be text/plain; charset=UTF-8; markup=markdown. Then the markdown add-on could work selectively and all would be well.
A small matter but would make a significant difference to the user experience!