InsightIPTV

Hi Guys! I have each month round about 300+ overdue invoices and need to know how to send the a individual email how to pay or better to say which payment option they can choose as well. I know that i can send "Reminder" with one click but i need to send them a individual mass email with individual and unique text but to ALL overdue invoices from this day or at all! Hope you can help asap. Thanks