[Postfix] Fix HELO name

data/Dockerfiles/postfix/postfix.sh

@@ -341,9 +341,11 @@ EOF
 
 sed -i '/User overrides/q' /opt/postfix/conf/main.cf
 echo >> /opt/postfix/conf/main.cf
-if [ -f /opt/postfix/conf/extra.cf ]; then
-  cat /opt/postfix/conf/extra.cf >> /opt/postfix/conf/main.cf
-fi
+touch /opt/postfix/conf/extra.cf
+sed -i '/myhostname/d' /opt/postfix/conf/extra.cf
+echo -e "myhostname = ${MAILCOW_HOSTNAME}\n$(cat /opt/postfix/conf/extra.cf)" > /opt/postfix/conf/extra.cf
+
+cat /opt/postfix/conf/extra.cf >> /opt/postfix/conf/main.cf
 
 if [ ! -f /opt/postfix/conf/custom_transport.pcre ]; then
   echo "Creating dummy custom_transport.pcre"

docker-compose.yml

@@ -254,7 +254,7 @@ services:
             - dovecot
 
     postfix-mailcow:
-      image: mailcow/postfix:1.57
+      image: mailcow/postfix:1.58
       depends_on:
         - mysql-mailcow
       volumes:
@@ -273,6 +273,7 @@ services:
         - DBPASS=${DBPASS}
         - REDIS_SLAVEOF_IP=${REDIS_SLAVEOF_IP:-}
         - REDIS_SLAVEOF_PORT=${REDIS_SLAVEOF_PORT:-}
+        - MAILCOW_HOSTNAME=${MAILCOW_HOSTNAME}
       cap_add:
         - NET_BIND_SERVICE
       ports: