The normal and escalated recipients function allows your to create a hierarchy in your schedules. So should you have no response after a certain amount of time has passed you can escalate who will receive your chase email to a different contact in your bookkeeping system.
To set this up simply go into a customer and under recipients you will see the list of the contacts you have in your bookkeeping system. To add more simply follow the link to the bookkeeping system and make changes. (Image shown is Xero but same process for other systems)
By using the "Normal" and "Escalated" column you can pick and choose who will receive the email based off of the schedule. You can also select someone to be CC'd into communication.
If you have one contact or dont want to use this functionality simply keep one contact as both "Normal" and "Escalated" and they will receive all communication.