---

- name: postmap sasl
  command: postmap hash:/etc/postfix/sasl-passwords

- name: postmap generic
  command: postmap hash:/etc/postfix/generic

- name: postmap virtual
  command: postmap hash:/etc/postfix/virtual

- name: newaliases
  command: newaliases

- name: restart postfix
  service:
    name: postfix
    state: restarted

...