Skip listen to v6 when SUBNET6 is not set

core/nginx/conf/nginx.conf

@@ -59,7 +59,9 @@ http {
     server {
       # Listen over HTTP
       listen 80;
+{% if SUBNET6 %}
       listen [::]:80;
+{% endif %}
       {% if TLS_FLAVOR == 'letsencrypt' %}
       location ^~ /.well-known/acme-challenge/ {
           proxy_pass http://127.0.0.1:8008;
@@ -91,13 +93,17 @@ http {
       # Listen on HTTP only in kubernetes or behind reverse proxy
       {% if KUBERNETES_INGRESS == 'true' or TLS_FLAVOR in [ 'mail-letsencrypt', 'notls', 'mail' ] %}
       listen 80;
+{% if SUBNET6 %}
       listen [::]:80;
+{% endif %}
       {% endif %}
 
       # Only enable HTTPS if TLS is enabled with no error and not on kubernetes
       {% if KUBERNETES_INGRESS != 'true' and TLS and not TLS_ERROR %}
       listen 443 ssl http2;
+{% if SUBNET6 %}
       listen [::]:443 ssl http2;
+{% endif %}
 
       include /etc/nginx/tls.conf;
       ssl_stapling on;
@@ -341,7 +347,9 @@ mail {
     # SMTP is always enabled, to avoid losing emails when TLS is failing
     server {
       listen 25;
+{% if SUBNET6 %}
       listen [::]:25;
+{% endif %}
       {% if TLS and not TLS_ERROR %}
       {% if TLS_FLAVOR in ['letsencrypt','mail-letsencrypt'] %}
       ssl_certificate /certs/letsencrypt/live/mailu/fullchain.pem;
@@ -363,7 +371,9 @@ mail {
     {% if not TLS_ERROR %}
     server {
       listen 143;
+{% if SUBNET6 %}
       listen [::]:143;
+{% endif %}
       {% if TLS %}
       starttls only;
       {% endif %}
@@ -376,7 +386,9 @@ mail {
 
     server {
       listen 110;
+{% if SUBNET6 %}
       listen [::]:110;
+{% endif %}
       {% if TLS %}
       starttls only;
       {% endif %}
@@ -389,7 +401,9 @@ mail {
 
     server {
       listen 587;
+{% if SUBNET6 %}
       listen [::]:587;
+{% endif %}
       {% if TLS %}
       starttls only;
       {% endif %}
@@ -401,7 +415,9 @@ mail {
     {% if TLS %}
     server {
       listen 465 ssl;
+{% if SUBNET6 %}
       listen [::]:465 ssl;
+{% endif %}
       protocol smtp;
       smtp_auth plain login;
       auth_http_header Auth-Port 465;
@@ -409,7 +425,9 @@ mail {
 
     server {
       listen 993 ssl;
+{% if SUBNET6 %}
       listen [::]:993 ssl;
+{% endif %}
       protocol imap;
       imap_auth plain;
       auth_http_header Auth-Port 993;
@@ -419,7 +437,9 @@ mail {
 
     server {
       listen 995 ssl;
+{% if SUBNET6 %}
       listen [::]:995 ssl;
+{% endif %}
       protocol pop3;
       pop3_auth plain;
       auth_http_header Auth-Port 995;

core/postfix/conf/main.cf

@@ -14,7 +14,7 @@ queue_directory = /queue
 message_size_limit = {{ MESSAGE_SIZE_LIMIT }}
 
 # Relayed networks
-mynetworks = 127.0.0.1/32 [::1]/128 {{ SUBNET }} {% if SUBNET6 %}{{ "[{}]/{}".format(*SUBNET6.split("/")) }}{% endif %} {% if RELAYNETS %}{{ RELAYNETS.split(",") | join(" ") }}{% endif %}
+mynetworks = 127.0.0.1/32 {{ SUBNET }} {% if SUBNET6 %}[::1]/128 {{ "[{}]/{}".format(*SUBNET6.translate({91: None, 93: None}).split("/")) }}{% endif %} {% if RELAYNETS %}{{ RELAYNETS.split(",") | join(" ") }}{% endif %}
 
 # Empty alias list to override the configuration variable and disable NIS
 alias_maps =
@@ -121,7 +121,7 @@ smtpd_relay_restrictions =
 
 unverified_recipient_reject_reason = Address lookup failure
 
-smtpd_authorized_xclient_hosts={{ SUBNET }}{% if SUBNET6 %},[{{ SUBNET6 }}]{% endif %}
+smtpd_authorized_xclient_hosts={{ SUBNET }}{% if SUBNET6 %},{{ "[{}]/{}".format(*SUBNET6.translate({91: None, 93: None}).split("/")) }}{% endif %}
 
 ###############
 # Milter

webmails/nginx-webmail.conf

@@ -1,6 +1,8 @@
 server {
     listen 80 default_server;
+{% if SUBNET6 %}
     listen [::]:80 default_server;
+{% endif %}
     resolver {{ RESOLVER }} valid=30s;
 
 {% if WEBMAIL == 'roundcube' %}