WooCommerce Newsletter Subscription to care about is the one that has all your past clients in it.

WooCommerce Newsletter Subscription Features

• Optionally subscribe to your customers when their orders reach a specific status.
• Create a new sales channel with people already interested in you in no time.
• Includes a dashboard widget with the main statistics you need to keep track of your performance.
• Integrates smoothly into your checkout.
• Gather your next recurrent customers in one mailing list that you can target with promotions and other actions to increase your sales.
• Customers can subscribe anywhere on your site thanks to our subscription widget.