Site Reviews includes and uses the Action Scheduler library to queue notification emails and the standard WordPress mail functions to send emails. However, you may experience problems if WP-Cron is not working, or if your WordPress settings and server configuration are incorrect.
Your WP-Cron service may have stopped if the Action Scheduler has a lot of pending actions. You can check the status of WP-Cron with the WP-Cron Status Checker plugin.
If there are no pending actions in the “Site Reviews > Tools > Scheduled Actions”, please verify that you are sending from an email address that uses the same domain as your website. For example, if your website is https://reviews.com, the email address you are sending from should end with @reviews.com. You can change the email address from which notifications are sent in the plugin settings. Alternatively, use the WP Mail SMTP plugin to reconfigure WordPress to use a SMTP provider (see also: Easy SMTP email settings for WordPress).
Finally, you can use the Check & Log Email plugin to verify that your website can successfully send emails.
