Two things that a conventional email system might offer, which I think Discourse doesn’t presently, are
- an undo, to un-send a thing, which in reality means the thing is scheduled to go after some short time interval
- a scheduled send, which means the poster decides the thing will be posted say at noon tomorrow, and that gives them time to revisit the content or the decision to send at all
Neither of these is quite the same as the idea of having a trusted party to approve things in future.