---
- name: Stat postfix main.cf
  ansible.builtin.stat:
    path: /etc/postfix/main.cf
  register: postfix_main_cf
  tags:
    - packages
    - postfix

- name: Configure Postfix disable_vrfy_command
  become: true
  ansible.builtin.lineinfile:
    regexp: "^disable_vrfy_command"
    dest: /etc/postfix/main.cf
    line: "disable_vrfy_command = yes"
    state: present
  when: postfix_main_cf.stat.exists
  tags:
    - packages
    - postfix

- name: Configure Postfix inet_interfaces
  become: true
  ansible.builtin.lineinfile:
    regexp: "^inet_interfaces"
    dest: /etc/postfix/main.cf
    line: "inet_interfaces = loopback-only"
    state: present
  when: postfix_main_cf.stat.exists
  tags:
    - packages
    - postfix

- name: Configure Postfix smtpd_banner
  become: true
  ansible.builtin.lineinfile:
    regexp: "^smtpd_banner"
    dest: /etc/postfix/main.cf
    line: 'smtpd_banner = \$myhostname - ESMTP'
    state: present
  when: postfix_main_cf.stat.exists
  tags:
    - packages
    - postfix

- name: Configure Postfix smtpd_client_restrictions
  become: true
  ansible.builtin.lineinfile:
    regexp: "^smtpd_client_restrictions"
    dest: /etc/postfix/main.cf
    line: "smtpd_client_restrictions = permit_mynetworks,reject"
  when: postfix_main_cf.stat.exists
  tags:
    - packages
    - postfix
...