server/etc/apt/apt.conf.d/99update-notifier

DPkg::Post-Invoke {"if [ -d /var/lib/update-notifier ]; then touch /var/lib/update-notifier/dpkg-run-stamp; fi; /usr/lib/update-notifier/update-motd-updates-available 2>/dev/null || true";};
APT::Update::Post-Invoke-Success {"/usr/lib/update-notifier/update-motd-updates-available 2>/dev/null || true";};