Reviews are anonymous by default so customers can easily leave a review. You can make it optional or mandatory for customers to add their email address to reviews. By requiring customer email addresses for reviews, you can:
Check if a review is from a real customer.
Contact customers who have problems.
To prevent anonymous reviews:
Log in to your eCom Back Office and click Settings in the sidebar on the left.
Click Advanced at the bottom of the column General Settings.
Scroll down to the REVIEWS section and select Required het from the dropdown menu labeled Email.
Click on Save.