diff --git a/mixed/compose.yml b/mixed/compose.yml
index 606b72b..1630643 100755
--- a/mixed/compose.yml
+++ b/mixed/compose.yml
@@ -347,7 +347,7 @@ services:
       - SIGNUPS_ALLOWED=false
       - SIGNUPS_VERIFY=false
       - SMTP_PORT=587
-      - SMTP_SECURITY=tls
+      - SMTP_SECURITY=force_tls
     ports:
       - 8089:80/tcp
     restart: always