I can't tell what the plugin will do if I choose Recurring billing. I am using PayPal for payment. I have recurring customers but nothing is set up recurring at PayPal. Do I have to do something there to use it in the plugin? I can't use the Send Automatically option because I need the email customized to that invoice (1st quarter, 2nd quarter, or January, February, etc.)
I am also confused about the Due Date. How do I display it on the invoice page and how do I set it if it is not recurring? It would be nice to have an option to default the due date to a number of days.