How to permanently remove someone from recipient submissions list?

I have removed someone from the receipt of submissions list but they keep getting a copy of submissions 

If the email recipient has been removed from the email notification, they will not be able to receive the emails after submitting the form.

Please check if any conditions set on the form to change the email recipient of the notification. If the issue still persists, please let us know the form and the notification that you are experiencing the issue so that we can take a look and assist you further.

Thanks!