Add smtpd helo restrictions.

defaults/main.yml

@@ -20,6 +20,7 @@ postfix_use_relay_host: '{{ postfix_relay_client }}'
 postfix_biff: "no"
 postfix_append_dot_mydomain: "no"
 postfix_smtp_helo_required: "yes"
+postfix_helo_restrictions: True
 postfix_smtp_delay_reject: "yes"
 postfix_smtp_disable_vrfy: "yes"
 

templates/main.cf.j2

@@ -579,6 +579,14 @@ smtpd_milters =
 {% endif %}
 
 {% if postfix_smtpd_server %}
+{% if postfix_helo_restrictions %}
+smtpd_helo_restrictions =
+    permit_mynetworks
+    reject_invalid_helo_hostname
+    reject_non_fqdn_helo_hostname
+    reject_unknown_helo_hostname
+{% endif %}
+
 smtpd_recipient_restrictions =
 {% for recipient_rule in postfix_smtpd_server_restrictions %}
         {{ recipient_rule }}