As I mentioned in an old comment, I use cron-apt to keep my Debian servers fresh.

This post is just a quick reminder to my future self, about how I setup cron-apt on my machines.

First we install the package:

$ aptitude install cron-apt

Then we configure it:

$ sed -i 's/# MAILON="error"/MAILON="always"/g' /etc/cron-apt/config
$ sed -i 's/# MAILTO="root"/MAILTO="user@example.com"/g' /etc/cron-apt/config

That's it !