Earlier quoted context omitted.
So you are saying these bot accounts have opted in to receiving emails? You don't validate the email when someone signs up?
The site terms and conditions are displayed very publicaly and accessible to anyone who cares to read them. By entering your email address you are opting-in for transaction related emails, including new order confirmations, shipment notifications, and yes cart reminders. It's spelled out for you. It's the same for almost every ecommerce site. That's different than marketing emails, which require a separate explicit o…
You realize that you can't send marketing emails without double opt-in, right? "Hey, you forgot to buy these ..." is definitely a marketing email.