To disable the sending of listchanges information from APT run the following command:

dpkg-reconfigure apt-listchanges

Then select None as Method to be used to display changes. Confirm all other requests with the default selected value.

If enabled the debsecan-package will send a daily email with all vulnerabilities in installed packages on the system. To disable remove the MAILTO and the cron entry from the file /etc/cron.d/debsecan by commenting them out.

When getting the follwing error when running apt update:

Failed to start apt-news.service: Unit apt-news.service is masked.
Failed to start esm-cache.service: Unit esm-cache.service is masked.

Just run:

sudo systemctl mask apt-news.service
sudo systemctl mask esm-cache.service
sudo mv /etc/apt/apt.conf.d/20apt-esm-hook.conf /etc/apt/apt.conf.d/20apt-esm-hook.conf.disabled