Email is just fine for me, I don't understand why people need to pretend they reinvent it every other week (social email, todo list email...). The only thing I

Email is just fine for me, I don't understand why people need to pretend they reinvent it every other week (social email, todo list email...). The only thing I'm missing is on the technical side, a transaction system like you describe. How great would it be if all the servers could reply to my mail client : I have received your email it isn't considered spam and the end user got it.