Has anyone tried to create a custom dunning functionality? Basically, we want to send dunning letters that have different email messages based on the no. of days past due. Also, we want to send at the customer-level which means that if 2 or more open invoices have the same no. of days past overdue, they should be sent in one email only to the customer. Should we use a workflow based on customer record type? Should we use separate email templates or one email template with multiple if statements based on no. of days past overdue? Should we use a transaction or customer saved search for the scheduling? Any other considerations? Thank you!