Can I hide system defined lists to be visible to users

Below is the requirement

When the contact email gets bounced back then through WS we update the contact field as Invalid email. Now the business wants when they try to add contacts under Accounts or Opportunity or Service Request it should not display contacts with Invalid email id and also throw an error message or completely stop them.

I tried out of box approach and suggested business to use a custom list which displays only contacts where the invalid email field is NULL.

But they want a more robust solution where no additional thinking is required. Or if I can get some sample code to implement through Client Side Extensions