In case an unduly abandoned cart email was sent to a customer who purchased something, review that your payment service always redirects a visitor back to a thank you (for your order) page where a successful order is communicated to your customer.
If a payment service doesn’t return and encourage a user to return to your site after a successful purchase, it means that a session is not treated as an successful order i.e. conversion as Nosto’s order tagging on the thank you page is not loaded, consequently meaning that order event is not sent. This on the other hands skews analytics and all Nosto features and as a most visible part, an unduly abandoned cart email is sent to customers.
Additionally, if your payment service doesn’t send customers back to your site, report the incidents by sending a few example email addresses of customers who received an unduly cart email to Nosto’s support as we can then review the case and add a manual by-pass rule preventing abandoned cart emails in case a user leaves your site and starts the payment process.
The error might also be caused if your thank you page is hosted and located under a different hostname to your site. In such a case, add your thank you page’s hostname under account settings as an additional hostname.