With this plugin, Store owner can add multiple blacklisted email address. So blacklist customer can not place an order with this email address in your shop.
Email: Enter email addresses of the users that you want to block.
Bulk upload block an email address: With this option, you can upload bulk an email address by demo format xlsx file here
Custom error messages for blacklisted email user
With this setting, you can add custom error message which you want a show to a user when blacklist email found.