diff --git a/roles/docker/defaults/main.yml b/roles/docker/defaults/main.yml
index 67078c3..5df5d4f 100644
--- a/roles/docker/defaults/main.yml
+++ b/roles/docker/defaults/main.yml
@@ -42,6 +42,7 @@ services:
     domain: sso.{{ base_domain }}
     volume_folder: "{{ volume_root_folder }}/keycloak"
     version: "20.0"
+    allowed_sender_domain: true
 
   restic:
     file: restic_backup.yml