When sending a series of cart abandonment messages to those who add your course in their shopping cart but left without completing their purchase order, your leads might respond and go back to where they left to purchase the course.
In this case, you should have a workflow which says that once they complete their order, you wait for a few minutes then send them a confirmation email with the details of the course and remove them from the cart abandonment automation.
** Note: Your automation will not work properly if you do not clearly set up all the required conditions.