Multiple customer created by using same email id prestashop 1.5.6.2

[kirubanidhi]

I Enabled guest checkout option in backoffice.

 

I Created one customer in guest checkout account by using email as "[email protected]" then i will go to create a another customer in customer group by using same email id as "[email protected]". 

 

I checking prestashop Backoffice ->Customers

 

There are two customer are created by using same email id in customer page.

 

I want to create only one customer by using [email protected] email id on both group(Customer and Guest)

 

How to avoid multiple customer create by using same email id.

Edited May 16, 2017 by kirubanidhi (see edit history)

[bellini13]

I want to create only one customer by using [email protected] email id on both group(Customer and Guest)

 

Why do you want to do that? 

 

A customer record in Prestashop cannot be a Guest and a Customer.  If the customer record was a Guest first, and now wants to become a Customer, then Prestashop is designed so that you would convert the Guest to a Customer