The markdown (square brackets) is part of my original post, so that’s why it’s probably in the plain text version. I guess it would be a nice discourse feature if it somehow transformed this particular markdown into something more like “plain text email” formatting, e.g. > - it’s probably worth submitting a discourse feature request for this.
The mail footer has (1) a perma-link to the original topic, (2) a legal notification about archiving replies, and (3) a sentence about why you’re receiving the email / how to unsubscribe.
(1) seems useful and I can imagine removing it would be quite confusing for navigating a long history of emails from the list. (2) is a legal requirement, (3) is good etiquette and probably a legal requirement in many places.