Create a new field by clicking on Entity | Contact | Keys | New.
In the Key definition dialogue, type Name and Email in the Display Name field.
Double-click on the First Name, Last Name, and Email Address fields under Available Attributes:
Click on Save and Close.
Navigate to contacts and try creating two contacts with the same first name, last name, and e-mail address. You will be prompted with the Duplicate Record error, as shown in the following screenshot:
