Problem with REST API while creating contacts

Content

Hi,

I am creating contacts from REST API with first name, last name and email address. Considering a happy path, I could create contacts with different values but when i hit the API again, I could create contacts with same email address that appends "001" and "002" at the end of the email address and so on in a consecutive manner. How can i stop the API to create a contact with same email?

 

Version

Nov 2016

Code Snippet

             REST API: https://mysite.custhelp.com/services/rest/connect/v1.3/contacts

{
    "name":
    {
        "first" : "First Name demo",
        "last" : "Last Name demo"
    },
"emails" :
    {
        "addressType" :
        {
            "lookupName": "Email - Primary"
        },