By default on WHM system emails are sent to root@hostname – but it you don’t have that email address created on the server, email delivery will be failed and the following error message can be seen on the Sent Summary page in WHM:
root@hostname is undeliverable: root cannot accept local mail deliveries
You can either create this email address root@hostname or change the email address to which system emails are delivered on the following page: WHM > Edit System Mail Preferences
