diff --git a/README.md b/README.md
index b517c49..23857c3 100644
--- a/README.md
+++ b/README.md
@@ -38,6 +38,8 @@ None
  * `postfix_mynetworks` [default: `['127.0.0.0/8', '[::ffff:127.0.0.0]/104', '[::1]/128']`]: The list of "trusted" remote SMTP clients that have more privileges than "strangers"
  * `postfix_inet_interfaces` [default: `all`]: Network interfaces to bind ([see](http://www.postfix.org/postconf.5.html#inet_interfaces))
  * `postfix_inet_protocols` [default: `all`]: The Internet protocols Postfix will attempt to use when making or accepting connections ([see](http://www.postfix.org/postconf.5.html#inet_protocols))
+ * `postfix_smtp_ipv4_bind` [optional]: Outbound network interfaces to use (IPv4) ([see](http://www.postfix.org/postconf.5.html#smtp_bind_address))
+ * `postfix_smtp_ipv6_bind` [optional]: Outbound network interfaces to use (IPv6) ([see](http://www.postfix.org/postconf.5.html#smtp_bind_address6))
 
  * `postfix_relayhost` [default: `''` (no relay host)]: Hostname to relay all email to
  * `postfix_relayhost_mxlookup` [default: `false` (not using mx lookup)]: Lookup for MX record instead of A record for relayhost
diff --git a/templates/etc/postfix/main.cf.j2 b/templates/etc/postfix/main.cf.j2
index c33e305..eaecaf3 100644
--- a/templates/etc/postfix/main.cf.j2
+++ b/templates/etc/postfix/main.cf.j2
@@ -88,6 +88,12 @@ inet_interfaces = {{ postfix_inet_interfaces }}
 {% else %}
 inet_interfaces = {{ postfix_inet_interfaces | join(', ') }}
 {% endif %}
+{% if postfix_smtp_ipv4_bind is defined %}
+smtp_bind_address = {{ postfix_smtp_ipv4_bind }}
+{% endif %}
+{% if postfix_smtp_ipv6_bind is defined %}
+smtp_bind_address6 = {{ postfix_smtp_ipv6_bind }}
+{% endif %}
 {% if postfix_inet_protocols is string %}
 inet_protocols = {{ postfix_inet_protocols }}
 {% else %}