---
- name: Install postfix
  apt:
    name: postfix

- name: Configure postfix
  template:
    src: "{{ item.src }}"
    dest: "{{ item.dest }}"
    owner: root
    group: root
    mode: u=rw,g=,o=
  loop:
    - src: main.cf.j2
      dest: /etc/postfix/main.cf
    - src: master.cf.j2
      dest: /etc/postfix/master.cf
    - src: virtual.j2
      dest: /etc/postfix/virtual
    - src: vmailbox.j2
      dest: /etc/postfix/vmailbox
  notify:
    - Reload postfix

- name: Enable and start postfix
  systemd:
    name: postfix.service
    state: started
    enabled: true
...