cPGuard does not send emails to the administrators each time it detects an infection. As we believe it may increase email flow during any attack, we have decided to apply some logic and reduce alert emails. So based on the logic, it will collect data and process it all together immediately after sending an alert. This will help to reduce email count and less hassle for you to manage the alert emails.
Additionally please go to WHM >> Plugins >> cPGuard >> Settings >> Notifications and make sure to specific your email address [ one address per text box ] properly.