Apptha's Out Stock notification is a Magento stock management extension that notifies your customers whenever your “Out of Stock” products shift to “In Stock”. The magento out of stock message allows the store owners to notify users on the back stock products via the user's e-mail. The extension when installed, enables the store owners to pop-up a message box for the Out-of-Stock products, indicating the customer to enter their email id to get notified when the product is back to stock.