It does not matter if your paypal email address is different from your communication email address with any MSC. It matters that you put a valid paypal email address in your profile under your payment method, if paypal is your choice of payment.
DON'T SHOP FOR THEM. They will do anything they can to not pay. Give you three hours to make a fix, I enter it a half hour before due and they still cancelled it. Questions are so specific you would need a tape recorder during your shop to do it per their requirements.