unattended_upgrades: apt-listchanges sends no mails

unattended_upgrades/tasks/main.yml

@@ -23,6 +23,21 @@
     dest: /etc/apt/apt.conf.d/52unattended-upgrades-local
     mode: "0644"
 
+# Debian installs apt-listchanges with email_address=root, which mails the NEWS of every
+# unattended upgrade through the mail relay.
+- name: Check for the apt-listchanges config
+  ansible.builtin.stat:
+    path: /etc/apt/listchanges.conf
+  register: unattended_upgrades_listchanges
+
+- name: Disable the apt-listchanges mails
+  ansible.builtin.lineinfile:
+    path: /etc/apt/listchanges.conf
+    regexp: '^email_address='
+    line: email_address=none
+    insertafter: '^\[apt\]'
+  when: unattended_upgrades_listchanges.stat.exists
+
 - name: Enable the apt timers
   ansible.builtin.systemd:
     name: "{{ item }}"