diff --git a/cli/build/defaults/users.py b/cli/build/defaults/users.py
index 626df276..1cee0020 100644
--- a/cli/build/defaults/users.py
+++ b/cli/build/defaults/users.py
@@ -189,7 +189,7 @@ def parse_args():
 
 def main():
     args = parse_args()
-    primary_domain = '{{ PRIMARY_DOMAIN }}'
+    primary_domain = '{{ SYSTEM_EMAIL.DOMAIN }}'
     become_pwd = '{{ lookup("password", "/dev/null length=42 chars=ascii_letters,digits") }}'
 
     try:
diff --git a/roles/web-app-mailu/config/main.yml b/roles/web-app-mailu/config/main.yml
index bef7db49..330e12e8 100644
--- a/roles/web-app-mailu/config/main.yml
+++ b/roles/web-app-mailu/config/main.yml
@@ -1,7 +1,7 @@
 oidc:
-  email_by_username:      true                    # If true, then the mail is set by the username. If wrong then the OIDC user email is used
-  enable_user_creation:   true                    # Users will be created if not existing
-domain:                   "{{ PRIMARY_DOMAIN }}"  # The main domain from which mails will be send \ email suffix behind @                              
+  email_by_username:      true                        # If true, then the mail is set by the username. If wrong then the OIDC user email is used
+  enable_user_creation:   true                        # Users will be created if not existing
+domain:                   "{{ SYSTEM_EMAIL.DOMAIN }}" # The main domain from which mails will be send \ email suffix behind @                              
 features:
   matomo:                 true
   css:                    false
@@ -12,7 +12,9 @@ features:
 server:
   domains:
     canonical:
-      - "mail.{{ PRIMARY_DOMAIN }}"
+      - "{{ SYSTEM_EMAIL.HOST }}"
+    alias:
+      - "mailu.{{ PRIMARY_DOMAIN }}"
   csp:
     flags:
       style-src: