Save the cart in the database for abandoned cart email follow up
The current functionality will lead a user to an empty cart when clicking the cart link in an abandoned cart follow up email from another device than the device that was used to abandon the cart.
The cart should be temporarily saved in the database so that the user can get back to the cart across devices. Consider a scenario where a user has to abandon their cart at their work computer and get the email at their phone on the bus home. They cannot complete their purchase if they were not logged in, because the cart is empty.