I’ve finally setup reply by email for my Discourse forum, but unfortunately parsing of replies seems suboptimal and the original message is not stripped. My forum is in Italian, but that should be accounted for, at least judging by some earlier bug reports about this same issue. I’ve seen a few other topics here on Meta (and there are probably older ones as well):
I don’t use Gmail, that probably accounts for 50% of my users alone and should be covered, but I wonder if there’s a more robust way to support quirks of other email clients (e.g. mobile email clients, since replying to email from mobile is one of the use cases that Discourse wants to support, I think). Of course I can just suggest users to strip entirely the original message or leave only short quotes if they like, but … I’m sure Discourse can handle this better!