Also stay in the loop with what's going on through these awesome links:
Just like in MX4 Review - you could print and then email or email and then print - any combination until you exited Review. To do both a print and an email send with Quick Pay you click on Receipt you can do one or the other but when it finishes that task it exits the Quick Pay and you need to go to Payments - open the payment, click on Receipt, and then you can do the second task.