diff --git a/webserver/docker_mail/templates/mailu.env b/webserver/docker_mail/templates/mailu.env
index 8c370d0afd97386d4fb2fae7e5332aef946449ef..75723d04fec6eea32fccfce603df671aa24c0f04 100644
--- a/webserver/docker_mail/templates/mailu.env
+++ b/webserver/docker_mail/templates/mailu.env
@@ -5,6 +5,9 @@
 # Set Version 
 MAILU_VERSION=2.0.4
 
+# enable IPv6
+SUBNET6=fd00:dead:beef:25::/64
+
 # Autocreate Admin User 
 INITIAL_ADMIN_ACCOUNT=mailadmin
 INITIAL_ADMIN_DOMAIN={{ domain }}