You should consider using a "bounce back to sender" feature. This feature notifies you when an email cannot be delivered. You can see the reason for the bounce and take action. It helps you clean your list by identifying invalid email addresses. You can remove these addresses to avoid further bounces. You must be careful with bounce back emails. Sometimes, they can be too frequent or unnecessary. You may want to filter them to focus on significant issues. Overall, a bounce back to sender feature helps you improve email deliverability and maintain a clean email list.