Emailing a receipt for a deposit

Hi, I take a £50 deposit prior to some of my orders, but I don’t seem to be able to email a receipt without manually entering in the email address. Is there a quick and simple way around this please?

How do you expect the program to know where you want to send the receipt?

I have included the customers name from the drop down choice in payer and after putting it under account receivable, a choice of customer names come up. I have clicked the appropriate name.

Email addresses are not automatically filled.

When I send out a quote or invoice, I am able to email automatically. I am respectfully asking if there is some way I can do this when sending out deposit receipts as it is an important and time consuming part of my business? I have no idea how programmes work. I am a florist.