diff --git a/roles/docker/defaults/main.yml b/roles/docker/defaults/main.yml
index a44c0d9..72ddef4 100644
--- a/roles/docker/defaults/main.yml
+++ b/roles/docker/defaults/main.yml
@@ -223,8 +223,9 @@ services:
     domain: "forum.{{ base_domain }}"
     volume_folder: "{{ volume_root_folder }}/nodebb"
     pre_deploy_tasks: true
-    version: 4.x
+    version: "4.0.3"
     mongodb_version: 7-jammy
+    allowed_sender_domain: true
 
   ### Uptime monitoring ###
   uptime_kuma:
diff --git a/roles/docker/templates/compose-files/nodebb.yml.j2 b/roles/docker/templates/compose-files/nodebb.yml.j2
index e9bed3e..d336fd5 100644
--- a/roles/docker/templates/compose-files/nodebb.yml.j2
+++ b/roles/docker/templates/compose-files/nodebb.yml.j2
@@ -14,6 +14,7 @@ services:
     restart: always
     networks:
       - default
+      - postfix
       - external_services
     volumes:
       - ./build:/usr/src/app/build:rw
@@ -29,5 +30,7 @@ services:
       - mongodb
 
 networks:
+  postfix:
+    external: true
   external_services:
     external: true