diff --git a/pyquarantine/__init__.py b/pyquarantine/__init__.py
index 7472c63..011e63a 100644
--- a/pyquarantine/__init__.py
+++ b/pyquarantine/__init__.py
@@ -296,6 +296,9 @@ class ModifyMilter(Milter.Base):
                     f"current template variables: {self.msginfo['vars']}")
                 if milter_action is not None:
                     break
+                elif not self.msginfo["rcpts"]:
+                    milter_action = ("DISCARD", None)
+                    break
 
             if milter_action is None:
                 self._replacebody()
@@ -303,6 +306,7 @@ class ModifyMilter(Milter.Base):
                 action, reason = milter_action
                 if action == "ACCEPT":
                     self._replacebody()
+                    return Milter.ACCEPT
                 elif action == "REJECT":
                     self.setreply("554", "5.7.0", reason)
                     return Milter.REJECT
diff --git a/pyquarantine/storage.py b/pyquarantine/storage.py
index 40a66b3..aac45fe 100644
--- a/pyquarantine/storage.py
+++ b/pyquarantine/storage.py
@@ -395,7 +395,7 @@ class Quarantine:
         self._milter_action = None
         if "milter_action" in cfg["args"]:
             self._milter_action = cfg["args"]["milter_action"].upper()
-            assert self._milter_action in ["ACCEPT", "REJECT"], \
+            assert self._milter_action in ["ACCEPT", "REJECT", "DISCARD"], \
                 f"invalid milter_action '{cfg['args']['milter_action']}'"
 
         self._reason = None
@@ -513,5 +513,6 @@ class Quarantine:
 
         if self._milter_action is not None:
             milter.delrcpt(rcpts)
-            if not milter.msginfo["rcpts"]:
+            if self._milter_action in ["ACCEPT", "REJECT"] and \
+                    not milter.msginfo["rcpts"]:
                 return (self._milter_action, self._reason)