I’ve got exactly the same desire. Some orders from our customers need to be approved before we charge their credit card and process the order. We currently do this by sending emails to our sales team. Sometimes the sales team needs to get in touch with the original user, and wants to reply.
So for us, the original email headers could be:
From: "Web Order Bot" <order-bot@our-domain.com> # (clearly whitelisted)
To: discourse-ingestion@discoursemail.com
Reply-To: "New Customer" <never-been-to-discourse@customer.com>
Subject: Order 192831
What I’d love to see is a new Discourse staged user never-been-to-discourse@customer.com get created, and the incoming message be from that user. Our team could then reply directly to the customer in Discourse. As it stands, they reply to order-bot@our-domain.com which doesn’t work very well.
If we need to use an API to do this, can you point me to the APIs for creating new posts and staged users?