diff --git a/1.17.2/Dockerfile b/1.17.2/Dockerfile
index 3277915..e02ca2a 100644
--- a/1.17.2/Dockerfile
+++ b/1.17.2/Dockerfile
@@ -4,12 +4,12 @@ LABEL maintainer="Adam W Zheng <adam.w.zheng@icloud.com>"
 ENV S6_RELEASE 1.22.1.0
 ENV SIMPLESAMLPHP_RELEASE 1.17.2
 
-#Add S6 Overlay
+#Add s6-overlay
 ADD https://github.com/just-containers/s6-overlay/releases/download/v$S6_RELEASE/s6-overlay-amd64.tar.gz /tmp/
 RUN tar xzf /tmp/s6-overlay-amd64.tar.gz -C / --exclude="./bin" \
  && tar xzf /tmp/s6-overlay-amd64.tar.gz -C /usr ./bin
 
-#Install SimpleSAMLphp Requirements
+#Install simplesamlphp requirements
 RUN yum -y install centos-release-scl \
  && yum -y install rh-nginx114 rh-php72 rh-php72-php-fpm rh-php72-php-mbstring rh-php72-php-pdo rh-php72-php-ldap sclo-php72-php-pecl-memcached postfix \
  && sed -i 's/user = apache/user = nginx/' /etc/opt/rh/rh-php72/php-fpm.d/www.conf \
@@ -24,37 +24,37 @@ RUN echo -e 'server {\n    listen       80 default_server;\n    listen       [::
  && chown -Rv nginx:nginx /var/lib/php/session/ \
  && chmod a+t /var/lib/php/session/
 
-#Download SimpleSAMLphp, Archive must remain present for seeding post install.
+#Download simplesamlphp and retain archive for seeding
 RUN curl -Lo /var/simplesamlphp.tar.gz https://github.com/simplesamlphp/simplesamlphp/releases/download/v$SIMPLESAMLPHP_RELEASE/simplesamlphp-$SIMPLESAMLPHP_RELEASE.tar.gz \
  && tar xzf /var/simplesamlphp.tar.gz --directory /var \
  && mv /var/simplesamlphp-* /var/simplesamlphp \
  && touch /var/simplesamlphp/cert/breadcrumb \
  && touch /var/simplesamlphp/log/breadcrumb
 
-#Redirect NGINX Logs
+#Redirect nginx logs
 RUN ln -sf /dev/stdout /var/opt/rh/rh-nginx114/log/nginx/access.log \
  && ln -sf /dev/stderr /var/opt/rh/rh-nginx114/log/nginx/error.log
 
-#Add Service NGINX to be Monitored by S6
+#Add service nginx to s6-supervisor
 RUN mkdir -p /etc/services.d/nginx/ \
  && touch /etc/services.d/nginx/run \
  && echo '#!/usr/bin/execlineb -P' > /etc/services.d/nginx/run \
  && echo '/opt/rh/rh-nginx114/root/usr/sbin/nginx -g "daemon off;"' >> /etc/services.d/nginx/run
 
-#Add Service PHP-FPM to be Monitored by S6
+#Add service php-fpm to s6-supervisor
 RUN mkdir -p /etc/services.d/php-fpm/ \
  && touch /etc/services.d/php-fpm/run \
  && echo '#!/usr/bin/execlineb -P' > /etc/services.d/php-fpm/run \
  && echo '/opt/rh/rh-php72/root/usr/sbin/php-fpm' >> /etc/services.d/php-fpm/run --nodaemonize \
  && sed -i 's|pid = /run/php-fpm/php-fpm.pid|pid = /run/php-fpm.pid|g' /etc/opt/rh/rh-php72/php-fpm.conf
 
-#Add Service Postfix to be Monitored by S6
+#Add service postfix to s6-supervisor
 RUN mkdir -p /etc/services.d/postfix/ \
  && touch /etc/services.d/postfix/run \
  && echo '#!/usr/bin/execlineb -P' > /etc/services.d/postfix/run \
- && echo '/usr/sbin/postfix start' >> /etc/services.d/postfix/run
+ && echo '/usr/libexec/postfix/master -c /etc/postfix -d' >> /etc/services.d/postfix/run
 
-#Copy the SimpleSAMLphp CLI Install Script into the Container to be executed on startup
+#Copy the simplesamlphp install script into the container to be executed on startup
 COPY install-simplesamlphp.sh /etc/cont-init.d/
 RUN chmod u+x /etc/cont-init.d/install-simplesamlphp.sh
 
diff --git a/1.17.2/install-simplesamlphp.sh b/1.17.2/install-simplesamlphp.sh
index 9564a7f..2571751 100644
--- a/1.17.2/install-simplesamlphp.sh
+++ b/1.17.2/install-simplesamlphp.sh
@@ -302,6 +302,7 @@ if [ "$MTA_NULLCLIENT" == "true" ]; then
   sed -i "s|#myorigin = \$myhostname|myorigin = $POSTFIX_MYORIGIN|g" /etc/postfix/main.cf
   sed -i "s|#relayhost = \$mydomain|relayhost = $POSTFIX_RELAYHOST|g" /etc/postfix/main.cf
   sed -i "s|inet_interfaces = localhost|inet_interfaces = $POSTFIX_INETINTERFACES|g" /etc/postfix/main.cf
+  sed -i "s|inet_protocols = all|inet_protocols = ipv4|g" /etc/postfix/main.cf
   sed -i "s|mydestination = \$myhostname, localhost.\$mydomain, localhost|mydestination =  $POSTFIX_MYDESTINATION|1" /etc/postfix/main.cf
   if [ "$POSTFIX_MYDESTINATION" != "" ] ; then
     echo "[$0] [WARN] Only null client is supported in this image. POSTFIX_MYDESTINATION must be set to an empty string but was set to '$POSTFIX_MYDESTINATION'."