Add support for aditional smtp ports - OUT AND IN.

conf/main_ipv6.conf.sample

@@ -376,6 +376,19 @@ mm_udp_ports_out="$stansard_mattermost_udp_ports_out"
 smtpd_ips=""
 forward_smtpd_ips=""
 
+# Additional Ports on which SMTP Service should lsiten
+#
+# blank separated list of ports
+#
+smtpd_additional_listen_ports=""
+
+# Additional Ports for outgoing smtp traffic
+#
+# blank separated list of ports
+#
+smtpd_additional_outgoung_ports=""
+
+
 # - Mail Services (smtps/pop(s)/imap(s)
 # -
 mail_server_ips=""