diff --git a/gen-pmg.conf.5-opts.pl b/gen-pmg.conf.5-opts.pl
index fd928ce..b70ac1f 100755
--- a/gen-pmg.conf.5-opts.pl
+++ b/gen-pmg.conf.5-opts.pl
@@ -15,6 +15,11 @@ my $single_section = shift;
 my $found = 0;
 
 my $key_groups = {
+    'mail-ports' => [
+	'mail' , {
+	    int_port => 1,
+	    ext_port => 1,
+	}],
     'mail-relaying' => [
 	'mail' , {
 	    relay => 1,
diff --git a/pmgconfig.adoc b/pmgconfig.adoc
index 238dfab..157944a 100644
--- a/pmgconfig.adoc
+++ b/pmgconfig.adoc
@@ -253,15 +253,19 @@ endif::manvolnum[]
 
 TODO
 
+
 Ports
 ~~~~~
 
-
 ifndef::manvolnum[]
 image::images/screenshot/pmg-gui-mailproxy-ports.png[]
 endif::manvolnum[]
 
-TODO
+Those settings are saved to subsection 'mail' in `/etc/pmg/pmg.conf`,
+using the following configuration keys:
+
+include::pmg.mail-ports-conf-opts.adoc[]
+
 
 Options
 ~~~~~~~