Why am I unable to save or add a second email for one of my clients in the system? The system keeps indicating that this action is not allowed

Question:

Why am I unable to save or add a second email for one of my clients in the system? The system keeps indicating that this action is not allowed?

Answer:

This circumstance implies that there exists an additional contact record that has already saved the same email address. Therefore, if these two records correspond to the same individual, you have the option to merge them into a unified entry.