roles/postfix: Deploy Postfix MTA

The *postfix* role installs and configures the Postfix MTA. It currently
supports a number of modes, including direct transfer and relay. Relay
mode supports STARTTLS security and PLAIN authentication.

roles/postfix/handlers/main.yml

@@ -0,0 +1,12 @@
+- name: restart postfix
+  service:
+    name=postfix
+    state=restarted
+- name: reload postfix
+  service:
+    name=postfix
+    state=reloaded
+- name: rehash postfix sasl passwd table
+  command: postmap /etc/postfix/sasl_passwd
+- name: save firewalld configuration
+  command: firewall-cmd --runtime-to-permanent