WooCommerce makes it easy to bring your store online to sell digital and physical products. Your products will not be in stock all the time. You may also decide to put certain items on sale. Thanks to Product Alerts for WooCommerce, you can send notifications to your customers to keep them updated.
This plugin supports low stock, on-sale, and restocking alerts. Customers can simply sign up for the notification that applies to them, and the rest is easy. Admins can enable/disable alerts for individual products and make changes to email templates. Stats are provided, so you can clearly track e-mail alerts.
This plugin combines with WooCommerce to let your visitors subscribe to sales notifications and product updates. It is a paid plugin by bolderelements.