Thank you for invoice- Email Body

Hi all- when an invoice is paid, I like to send a thank you email (still waiting for this to be automated! Please & Thank you!), but it'd be great if the invoice was actually zero'd out in the email body. It states a zero balance on the invoice within DF, but not in the email body. It just makes it look confusing when I say "Thank you for your payment" and there's the total balance due. Maybe there should also be a line with amount received? Just some thoughts. Thanks!