Forwarded email conversations may have one indentation of quoting. However, multiple forwards can turn into a nightmarish situation. How about including an option for “max indent level for email replies” with a default value of 1. This way, if we want to include a forwarded message or two, we can do that.
How difficult would that be to implement? Wouldn’t the parser simply need to look for the leading “>” character in plain text emails and just decide whether or not to include that?
Additionally, since multiple levels of plain text forwarded messages just have more “>” “>>” “>>>” characters. Couldn’t you just include them and format them to collapse/expand within Discourse?