Customers > Newsletter Subscribers
From Shopnix Help
What are Newsletter Subscribers?
This feature is for customers to get the information about your store as if you announced that you are giving any offers or you added some new product in your store or any information which you want to share with the customers all these types of information customer can get via newsletter subscribers.
The customer can see the newsletter on the home page there by entering their mail id they can subscribe to this feature as shown in the image below.