How to Send Unique Coupons for Your Cart Abandonment in Mailchimp
In Mailchimp, there are built-in cart abandonment email automations for supported e-commerce platforms. These automations allow you to send out emails when someone abandons their cart. It's common to include an incentive in this email to increase the likelihood of purchase; in most cases, this comes in the form of a discount.
If you're using a Mailchimp Journey Automation to send out cart abandonment emails, then you can use an alternative method that allows you to insert the codes directly into the email itself instead of using the Redeem Link. Here's an article on How To Deliver Unique Codes in a Mailchimp Customer Journey Using Tags
Instead of including a fixed generic coupon in this email, we'll show you how to use Coupon Carrier to distribute unique coupons.
In Mailchimp, there isn't a way to include the discount code directly into the email itself. Instead, we need to add a link that, when clicked, will take the subscriber to a page where their code is assigned and shown. This page can also include a button to take the user to your website and even include their discount code in the URL, so they don't have to do any copy/paste. Here's how the Redeem Link works when clicked in an email: 
How to create a Redeem Link and insert it into your Cart Abandonment email
To create a Redeem Link and add it to your Mailchimp email, follow our article: How to add the Redeem Link to your Mailchimp email.
For more details on the Redeem Link feature and how to configure it, refer to our article: How to distribute unique codes in your emails using the Redeem Link.
One thing to note is that expiry dates configured in autogenerated code lists are based on the that the code was created. In the case of the Redeem Link, the code is created when the link is clicked the first time.
This means that if you send an email to someone and they wait a few days before they click the link, it's at that time the code is created, and the expiry date is based on. It might not be a problem for many businesses, but it's essential to understand how it works.