If you understand the reason why the purchase wasn't made, then you can finish it with the help of an email. For example, the customer
Wants to compare prices with another website,
Changes decision because of the high cost of delivery,
Doesn't find the button to buy, etc.
Perhaps the customer abandons cart because of the price or quality. The product recommendations solve this problem. Offer the subscriber other variants from the category he was interested in. You can set up the automatic addition of product recommendations to the email in eSputnik.