diff --git a/email_api/email_api/app.py b/email_api/email_api/app.py
index 7144e8d..ed7b0bb 100644
--- a/email_api/email_api/app.py
+++ b/email_api/email_api/app.py
@@ -172,11 +172,11 @@ def process_email(domain):
     if not recipients:
         return jsonify({'error': 'No recipients'}), 400
 
-    # … im Handler vor dem Weiterleiten …
-    recipient_domains = {addr.split('@')[-1] for addr in to_addrs}
+    # Domain-Check
+    recipient_domains = {addr.split('@')[-1] for addr in recipients}
     if not any(domain_exists(d) for d in recipient_domains):
-        print("Keine unserer Domains betroffen – skip.")
-        return {'statusCode': 200, 'body': 'Unknown domain'}
+        logger.info(f"[{request_id}] No known recipient domains ({recipient_domains}) – skip.")
+        return jsonify({'message': 'Unknown domain – skipped'}), 404
 
     with smtplib.SMTP(SMTP_HOST, SMTP_PORT) as smtp:
         smtp.sendmail(from_addr, recipients, email_bytes)