Back in stock requests
Add the Back in stock block to the product template. When the selected variant is sold out, customers can leave their email. The request arrives in your store inbox (Settings > Notifications sends contact form messages to your store email) with the product, variant and SKU, tagged back-in-stock.
Verso does not send automatic emails when stock returns; that needs an app. With the request in your inbox you can write back when the product is available again.