Host1Pus does not offer DDoS protection as a service, however, there is advanced firewall layer for VPS/Cloud services to filter bad traffic. When massive attack is creating threat on the host nodes, DDoS is mitigated by black holing the targeted IP address.
As a result of DDoS attack to server's IP address it will be temporary null routed in the Host1Plus core routers in order to keep the network stable. The null route is being automatically removed when attacks end and depends on the type of attack.
Notification about such incident will be automatically sent to the email address which is tied with your Host1Plus account. However, you may set additional automatic notifications of server resources and network limits by enabling them at Client Area since by default they are disabled: