Add possibility to set pool name for builtin ZoneMTA.

docker-entrypoint.sh

@@ -22,6 +22,7 @@ MYSQL_HOST=${MYSQL_HOST:-'mysql'}
 MYSQL_DATABASE=${MYSQL_DATABASE:-'mailtrain'}
 MYSQL_USER=${MYSQL_USER:-'mailtrain'}
 MYSQL_PASSWORD=${MYSQL_PASSWORD:-'mailtrain'}
+POOL_NAME=${POOL_NAME:-$(hostname)}
 
 # Warning for users that already rely on the MAILTRAIN_SETTING variable
 # Can probably be removed in the future.
@@ -64,6 +65,7 @@ else
         level: warn
       mongo: mongodb://${MONGO_HOST}:27017/zone-mta
       redis: redis://${REDIS_HOST}:6379/2
+      poolName: $POOL_NAME
 
     queue:
       processes: 5

server/lib/builtin-zone-mta.js

@@ -119,6 +119,13 @@ async function createConfig() {
             }
         },
 
+        pools: {
+            default: {
+              address: '0.0.0.0',
+              name: config.builtinZoneMTA.poolName || os.hostname()
+            }
+        },
+
         zones: {
             default: {
                 preferIPv6: false,