The HTTPMail proposal I mentioned here now has a discussion list. I've already received a few good comments, building a list of changes to make when I go back into editing the draft. However, I'm in no hurry to do so. People are still discussing¹ what they think it's for; which use cases they believe in or not, and which use cases I forgot to mention. That's a good discussion to have before nailing down what features it has to have.

[1] discussion so far on the general Apps Discuss mailing list; discussion really hasn't started up on the special purpose list yet.