services.postfix = {
    enable = true;
    relayHost = "mail.smtp2go.com";
    relayPort = 587;
    hostname = "mail.example.com";
    domain = "example.com";
    origin = "example.com";
    extraConfig = ''
      smtp_sasl_auth_enable = yes
      smtp_sasl_password_maps = texthash:/etc/nixos/secrets/postfix-sasl_passwd
      local_header_rewrite_clients = static:all
      append_dot_mydomain = yes
    '';
    networks = [
      "192.168.1.0/24"
      "172.17. 0.0/16"
    ];
  };