markdown email not converted to html

HTML emails hasn't yet been implemented. Right now, email notifications are plain text, and people can start reading and see what the reply is about, but not see any formatting. To read it "for real", they need to go to the blog.

Maybe it'd be nice to remove the Commonmark "commands" from the reply?
So the text looked like: "hello world! markdown"
instead of "# hello world! ## markdown"?