diff --git a/lissmilter.py b/lissmilter.py
index 0f57d96..f66dc66 100644
--- a/lissmilter.py
+++ b/lissmilter.py
@@ -75,9 +75,14 @@ def envrcpt(self, mail_to, *str):
                 # Should only happen if no AssociationGroup called 'STYR' has been created yet
                 pass
 
+        # Check if sender is valid before discarding any emails. A user sending 'from' the current domain, to an internal list, should add this as an extra email in the database.
         if not valid_sender:
-            self.setreply('554', '5.7.2', 'Sender <{}> not authorized for recipient ("{}"). Kontakta en ansvarig om du tycker det borde funka.'.format(self.envelope_from, to))
-            return Milter.REJECT
+            if f'@{mail_domain}' in self.envelope_from:
+                # https://pymilter.org/pymilter/namespacemilter.html#a4c8bad190cb7f54cea87f1182732ce83
+                return Milter.DISCARD
+            else:
+                self.setreply('554', '5.7.2', 'Sender <{}> not authorized for recipient ("{}"). Kontakta en ansvarig om du tycker det borde funka.'.format(self.envelope_from, to))
+                return Milter.REJECT
 
         self.change_subject = is_production_list or is_mass_list or is_summons_list