Unattended Upgrade

sudo apt update && sudo apt upgrade

sudo reboot

sudo apt install unattended-upgrades apt-listchanges bsd-mailx

sudo dpkg-reconfigure -plow unattended-upgrades

Configure automatic updates, enter:
sudo vi /etc/apt/apt.conf.d/50unattended-upgrades
Set up alert email ID:
Unattended-Upgrade::Mail "root@hg-system.com";
Automatically reboot Ubuntu box WITHOUT CONFIRMATION for kernel updates:
Unattended-Upgrade::Automatic-Reboot "true";
Finally edit the /etc/apt/listchanges.conf and set email ID:
email_address=root@hg-system.com