if you're looking for a feature to create double opt-in singup process in your shop - this is the right choice.
When your customer will create an account in your shop it will be disabled by default.
Customer will receive email message with activation link. To fully activate account it will be necessary to click on the activation link that customer will receive.
module is ready to work with PrestaShop 1.7 / 1.6 / 1.5
more informations about this addon you can find on official page here:
activate account with link