Shared email for multiple applicants

Summary:

Hi - we have run into this issue a couple of times and are looking for help. If we have one person that applied for a job using their personal email and got the job and then another person uses that same email when applying - the new applicants information will override the existing employees. We have text on the application page discouraging anyone from using a shared email address when applying - but there is no enforcement/validation to stop them from doing it. Has anyone else run into this? If so, can you share what you are doing to