Google review notifications are sent directly by Google.

To ensure you’re receiving these notifications or to enable them, go to your Google Business Profile.

Make sure to log in using the email address associated with the Google Business Listing you want to receive notifications for.

Once logged in, click on Settings from the menu on the left side of the screen.

Click on the toggle next to "Customer Reviews" and turn it on.

Typically Google will send an email notification 10 minutes after the review has been posted.