diff --git a/tools/utils.py b/tools/utils.py
index 4dc2b75..15869b0 100644
--- a/tools/utils.py
+++ b/tools/utils.py
@@ -51,7 +51,7 @@ def valid_username(username):
     return valid
 
 def set_mail_domain():
-    if MAIL_SERVER:
+    if app.config['MAIL_SERVER']:
         hostname = app.config['MAIL_DOMAIN']
     else:
         hostname = None