When you set up an Automatic Review Request, sending a follow-up email (2nd Request Email) is defaulted to being enabled.
It is possible to disable this, but we do not recommend doing that.
There are many reasons that a customer may not leave a review after the first review request email was sent, whether they opened it and forgot or missed the initial email in their inbox; sending a follow-up is a great way to job their memory and illicit a review from them.
A 2nd follow-up message will automatically trigger a certain time after the first message is sent if the customer still has not submitted any review through the review request.
You can find the follow-up section under Message Customization --> 2nd Request Email in your Automatic Review Request Campaign.