Package upgrades can be set up to install updates on Ubuntu without user intervention.

apt install unattended-upgrades

apt install bsd-mailx

This will install also install Postfix. mailx is what unattended upgrades uses to send external mail.

Edit /etc/apt/apt.conf.d/50unattended-upgrades. This file is mostly self explanatory. The options can be enabled by deleting un-commenting the line. At the very least, configure the following:

• Unattended-Upgrade::Mail “your@email.com”; to allow sending notifications to your e-mail address.
• Unattended-Upgrade::Automatic-Reboot “true”; to enable auto-reboots
• Unattended-Upgrade::Remove-Unused-Kernel-Packages “true”; to remove kernel-related packages. This is usually done using apt autoremove.
• Unattended-Upgrade::Remove-New-Unused-Dependencies “true”; - remove unneeded dependancies. Also manually done with apt autoremove.
• Unattended-Upgrade::Remove-Unused-Dependencies “false”; - remove unused packages, also, apt autoremove.

systemctl restart unattended-upgrades

Edit /etc/postfix/main.cf. Configuration of postfix is outside the scope of this article. For my purposes, I use a relay, so I edit and uncomment relayhost = to point to my relay.

mailx -vvv -s "Subject" your@e-mail.com

Press CTRL D to send the email.

unattended-upgrades --dry-run -–debug