3 files changed, 99 insertions, 0 deletions
diff --git a/src/mailman/rules/docs/rules.rst b/src/mailman/rules/docs/rules.rst
index 8b351650c..b3b0b9d15 100644
--- a/src/mailman/rules/docs/rules.rst
+++ b/src/mailman/rules/docs/rules.rst
@@ -30,6 +30,7 @@ names to rule objects.
     max-size True
     member-moderation True
     news-moderation True
+    no-senders True
     no-subject True
     nonmember-moderation True
     suspicious-header True
diff --git a/src/mailman/rules/no_senders.py b/src/mailman/rules/no_senders.py
new file mode 100644
index 000000000..7e8c78fa7
--- /dev/null
+++ b/src/mailman/rules/no_senders.py
@@ -0,0 +1,45 @@
+# Copyright (C) 2007-2017 by the Free Software Foundation, Inc.
+#
+# This file is part of GNU Mailman.
+#
+# GNU Mailman is free software: you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free
+# Software Foundation, either version 3 of the License, or (at your option)
+# any later version.
+#
+# GNU Mailman is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+# more details.
+#
+# You should have received a copy of the GNU General Public License along with
+# GNU Mailman.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Membership related rules."""
+
+from mailman.core.i18n import _
+from mailman.interfaces.rules import IRule
+from public import public
+from zope.interface import implementer
+
+
+@public
+@implementer(IRule)
+class NoSenders:
+    """The message has no senders rule."""
+
+    name = 'no-senders'
+    description = _('Match messages with no valid senders.')
+    record = True
+
+    def check(self, mlist, msg, msgdata):
+        """See `IRule`."""
+        if msg.sender:
+            return False
+        else:
+            msgdata['moderation_action'] = 'discard'
+            msgdata['moderation_sender'] = _('None')
+            msgdata.setdefault('moderation_reasons', []).append(
+                # This will get translated at the point of use.
+                'The message has no valid senders')
+            return True
diff --git a/src/mailman/rules/tests/test_no_senders.py b/src/mailman/rules/tests/test_no_senders.py
new file mode 100644
index 000000000..eb59dfe71
--- /dev/null
+++ b/src/mailman/rules/tests/test_no_senders.py
@@ -0,0 +1,53 @@
+# Copyright (C) 2016-2017 by the Free Software Foundation, Inc.
+#
+# This file is part of GNU Mailman.
+#
+# GNU Mailman is free software: you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free
+# Software Foundation, either version 3 of the License, or (at your option)
+# any later version.
+#
+# GNU Mailman is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+# more details.
+#
+# You should have received a copy of the GNU General Public License along with
+# GNU Mailman.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Test the `no_subject` header rule."""
+
+import unittest
+
+from mailman.app.lifecycle import create_list
+from mailman.email.message import Message
+from mailman.rules import no_senders
+from mailman.testing.layers import ConfigLayer
+
+
+class TestNoSubject(unittest.TestCase):
+    """Test the no_senders rule."""
+
+    layer = ConfigLayer
+
+    def setUp(self):
+        self._mlist = create_list('test@example.com')
+        self._rule = no_senders.NoSenders()
+
+    def test_message_has_no_sender(self):
+        msg = Message()
+        msgdata = {}
+        result = self._rule.check(self._mlist, msg, msgdata)
+        self.assertTrue(result)
+        self.assertEqual(msgdata['moderation_action'], 'discard')
+        self.assertEqual(msgdata['moderation_reasons'],
+                         ['The message has no valid senders'])
+        self.assertEqual(msgdata['moderation_sender'], 'None')
+
+    def test_message_has_sender(self):
+        msg = Message()
+        msg['From'] = 'anne@example.com'
+        msgdata = {}
+        result = self._rule.check(self._mlist, msg, msgdata)
+        self.assertFalse(result)
+        self.assertEqual(msgdata, {})