You may notice that some abandoned carts will not be followed up upon in Abandoned Cart emails.
This is actually a safety precaution to prevent old carts from being sent to users - let me explain :)
On some e-commerce platforms, the user's cart can remain "active" indefinitely. Ie, if someone browsed on your website a year ago and added items to their cart, did not check out and then came back a year later, that original cart may suddenly be "reactivated", just by the user browsing. If we were to followup on that cart, we might send out old products which are no longer being sold, old prices, etc.
Our mitigation against these "outdated carts" is that when sending out an abandoned cart email, we also look at the date the cart was created on. If that date is more than 90 days ago, we will not send an abandoned cart email. You can see if this is the case by looking at the "Created At" column in the Carts tab of your eCommerce Data view. In the example below, you can see that the second cart is an old one:
The way to mitigate this is by properly setting up your e-commerce platform so that carts expire faster, and do not stick around for so long - it usually makes no sense anyway.