Newsletter is an important marketing tool which helps you to inform clients regularly about shop's activities particularly as new products, promotions, discounts or loyalty programs. It is a great way to gain more customers to your store. Within the configuration, you can give a confirmation link that the customers need to click on to complete the subscription process. The process that requires customers to take a secondary step to verify the subscription is called the double opt-in1 method. Applying this method will reduce the spam to your newsletters.