diff --git a/app/controllers/api.py b/app/controllers/api.py
index ddbdf67..e6f364d 100644
--- a/app/controllers/api.py
+++ b/app/controllers/api.py
@@ -64,7 +64,7 @@ def get_comments_count(request):
 def new_comment(request):
 
     try:
-        data = request.get_json()
+        data = request.json
         logger.info(data)
 
         # validate token: retrieve site entity
diff --git a/app/controllers/mail.py b/app/controllers/mail.py
index 43d4d9c..0c7ba87 100644
--- a/app/controllers/mail.py
+++ b/app/controllers/mail.py
@@ -20,6 +20,6 @@ def new_mail(request):
 
     except:
         logger.exception("new mail failure")
-        abort(400)
+        return response.text('BAD_REQUEST', status=400)
 
-    return "OK"
+    return response.text('OK')
diff --git a/app/run.py b/app/run.py
index 57ccb40..02262c0 100644
--- a/app/run.py
+++ b/app/run.py
@@ -59,7 +59,7 @@ processor.start(template_path)
 logger.info("Start Stacosys application")
 
 # enable CORS
-cors = CORS(app, resources={r"/comments/*": {"origins": "*"}})
+cors = CORS(app, resources={r"/comments/*": {"origins": config.CORS_ORIGIN}})
 
 # tune logging level
 if not config.DEBUG:
diff --git a/config.py b/config.py
index 03e769f..4d969dc 100644
--- a/config.py
+++ b/config.py
@@ -11,7 +11,8 @@ MAIL_URL = "http://localhost:8025/mbox"
 
 HTTP_ADDRESS = "0.0.0.0"
 HTTP_PORT = 8000
-HTTP_WORKERS = 4
+HTTP_WORKERS = 1
+CORS_ORIGIN = "*"
 
 SALT = "BRRJRqXgGpXWrgTidBPcixIThHpDuKc0"