diff --git a/core/mail/protocol.py b/core/mail/protocol.py
index 0bddfd0..d88d31a 100644
--- a/core/mail/protocol.py
+++ b/core/mail/protocol.py
@@ -197,13 +197,19 @@ def receive_email(envelope, log=None):
     header_in_reply_to = parsed.get('In-Reply-To')
     header_message_id = parsed.get('Message-ID')
 
-    # if header_from != envelope.mail_from:
-    #    log.warning("Header from does not match envelope from")
-    #    log.info(f"Header from: {header_from}, envelope from: {envelope.mail_from}")
-    #
-    # if header_to != envelope.rcpt_tos[0]:
-    #    log.warning("Header to does not match envelope to")
-    #    log.info(f"Header to: {header_to}, envelope to: {envelope.rcpt_tos[0]}")
+    if header_from != envelope.mail_from:
+        log.warning("Header from does not match envelope from")
+        log.info(f"Header from: {header_from}, envelope from: {envelope.mail_from}")
+
+    if header_to != envelope.rcpt_tos[0]:
+        log.warning("Header to does not match envelope to")
+        log.info(f"Header to: {header_to}, envelope to: {envelope.rcpt_tos[0]}")
+
+    # handle undelivered mail 'MAILER-DAEMON@'
+
+    #if header_from.startswith('MAILER-DAEMON@'):
+    #    log.warning("Mail delivery failed")
+    #    return None, False, None, None
 
     if Email.objects.filter(reference=header_message_id).exists():  # break before issue thread is created
         log.warning("Email already exists")