I think it's rare that anyone would want to receive a copy of their own email. Part of the allure of OR is to streamline communication and eliminate extraneous emails in our inboxes and make the business as automated as possible. Anyone that wanted to see what emails they had previously sent can see it in the booking.
Yep, this is something we plan to overhaul. Later this year we're going to be working on a unified inbox/messaging that pulls in everything from everywhere into OwnerRez and at that point we'll smooth everything together.