33 files changed, 619 insertions, 45 deletions

diff --git a/setup.py b/setup.py
index 67fdb16bf..d6303676d 100644
--- a/setup.py
+++ b/setup.py
@@ -111,7 +111,7 @@ case second `m'.  Any other spelling is incorrect.""",
         'dnspython>=1.14.0',
         'falcon>=1.0.0rc1',
         'flufl.bounce',
-        'flufl.i18n',
+        'flufl.i18n>=2.0',
         'flufl.lock>=3.1',
         'lazr.config',
         'passlib',
diff --git a/src/mailman/chains/base.py b/src/mailman/chains/base.py
index 59125ba69..9507d8fbc 100644
--- a/src/mailman/chains/base.py
+++ b/src/mailman/chains/base.py
@@ -18,6 +18,7 @@
 """Base class for terminal chains."""
 
 from mailman.config import config
+from mailman.core.i18n import _
 from mailman.interfaces.chain import (
     IChain, IChainIterator, IChainLink, IMutableChain, LinkAction)
 from mailman.interfaces.rules import IRule
@@ -27,6 +28,24 @@ from zope.interface import implementer
 
 
 @public
+def format_reasons(reasons):
+    """Translate and format hold and rejection reasons.
+
+    :param reasons: A list of reasons from the rules that hit.  Each reason is
+        a string to be translated or a tuple consisting of a string with {}
+        replacements and one or more replacement values.
+    :returns: A list of the translated and formatted strings.
+    """
+    new_reasons = []
+    for reason in reasons:
+        if isinstance(reason, tuple):
+            new_reasons.append(_(reason[0]).format(*reason[1:]))
+        else:
+            new_reasons.append(_(reason))
+    return new_reasons
+
+
+@public
 @implementer(IChainLink)
 class Link:
     """A chain link."""
diff --git a/src/mailman/chains/headers.py b/src/mailman/chains/headers.py
index 6fc061fe4..01ba96971 100644
--- a/src/mailman/chains/headers.py
+++ b/src/mailman/chains/headers.py
@@ -105,6 +105,11 @@ class HeaderMatchRule:
             if isinstance(value, Header):
                 value = value.encode()
             if re.search(self.pattern, value, re.IGNORECASE):
+                msgdata['moderation_sender'] = msg.sender
+                with _.defer_translation():
+                    # This will be translated at the point of use.
+                    msgdata.setdefault('moderation_reasons', []).append(
+                        (_('Header "{}" matched a header rule'), str(value)))
                 return True
         return False
 
diff --git a/src/mailman/chains/hold.py b/src/mailman/chains/hold.py
index 4e72b685a..edc80da3c 100644
--- a/src/mailman/chains/hold.py
+++ b/src/mailman/chains/hold.py
@@ -24,7 +24,7 @@ from email.mime.text import MIMEText
 from email.utils import formatdate, make_msgid
 from mailman.app.moderator import hold_message
 from mailman.app.replybot import can_acknowledge
-from mailman.chains.base import TerminalChainBase
+from mailman.chains.base import TerminalChainBase, format_reasons
 from mailman.config import config
 from mailman.core.i18n import _
 from mailman.email.message import UserNotification
@@ -57,8 +57,8 @@ def _compose_reasons(msgdata, column=66):
     # Rules can add reasons to the metadata.
     reasons = msgdata.get('moderation_reasons', [_('N/A')])
     return NL.join(
-        [(SPACE * 4) + wrap(_(reason), column=column)
-         for reason in reasons])
+        [(SPACE * 4) + wrap(reason, column=column)
+         for reason in format_reasons(reasons)])
 
 
 def autorespond_to_sender(mlist, sender, language=None):
@@ -142,7 +142,7 @@ class HoldChain(TerminalChainBase):
         rule_misses = msgdata.get('rule_misses')
         if rule_misses:
             msg['X-Mailman-Rule-Misses'] = SEMISPACE.join(rule_misses)
-        reasons = msgdata.get('moderation_reasons', ['n/a'])
+        reasons = format_reasons(msgdata.get('moderation_reasons', ['n/a']))
         # Hold the message by adding it to the list's request database.
         request_id = hold_message(mlist, msg, msgdata, SEMISPACE.join(reasons))
         # Calculate a confirmation token to send to the author of the
@@ -251,7 +251,8 @@ also appear in the first line of the body of the reply.""")),
         # Log the held message.  Log messages are not translated, so recast
         # the reasons in the English.
         with _.using('en'):
-            reasons = msgdata.get('moderation_reasons', ['N/A'])
+            reasons = format_reasons(
+                msgdata.get('moderation_reasons', ['N/A']))
             log.info('HOLD: %s post from %s held, message-id=%s: %s',
                      mlist.fqdn_listname, msg.sender,
                      msg.get('message-id', 'n/a'), SEMISPACE.join(reasons))
diff --git a/src/mailman/chains/reject.py b/src/mailman/chains/reject.py
index 3284bba9f..31f66c8fa 100644
--- a/src/mailman/chains/reject.py
+++ b/src/mailman/chains/reject.py
@@ -20,7 +20,7 @@
 import logging
 
 from mailman.app.bounces import bounce_message
-from mailman.chains.base import TerminalChainBase
+from mailman.chains.base import TerminalChainBase, format_reasons
 from mailman.core.i18n import _
 from mailman.interfaces.chain import RejectEvent
 from mailman.interfaces.pipeline import RejectMessage
@@ -65,7 +65,7 @@ reasons:
 The original message as received by Mailman is attached.
 """).format(
     list_name=mlist.display_name,                   # noqa: E122
-    reasons=NEWLINE.join(reasons)
+    reasons=NEWLINE.join(format_reasons(reasons))
     ))
         bounce_message(mlist, msg, error)
         log.info('REJECT: %s', msg.get('message-id', 'n/a'))
diff --git a/src/mailman/chains/tests/test_headers.py b/src/mailman/chains/tests/test_headers.py
index cd4c932cc..2aae503b2 100644
--- a/src/mailman/chains/tests/test_headers.py
+++ b/src/mailman/chains/tests/test_headers.py
@@ -25,7 +25,8 @@ from mailman.chains.headers import HeaderMatchRule, make_link
 from mailman.config import config
 from mailman.core.chains import process
 from mailman.email.message import Message
-from mailman.interfaces.chain import DiscardEvent, HoldEvent, LinkAction
+from mailman.interfaces.chain import (
+    DiscardEvent, HoldEvent, LinkAction, RejectEvent)
 from mailman.interfaces.mailinglist import IHeaderMatchList
 from mailman.testing.helpers import (
     LogFileMark, configuration, event_subscribers,
@@ -343,3 +344,55 @@ A message body.
         # ...and are actually the identical objects.
         for link1, link2 in zip(links_1, links_2):
             self.assertIs(link1.rule, link2.rule)
+
+    def test_hold_returns_reason(self):
+        # Test that a match with hold action returns a reason
+        msg = mfs("""\
+From: anne@example.com
+To: test@example.com
+Subject: Bad subject
+Message-ID: <ant>
+
+body
+
+""")
+        msgdata = {}
+        header_matches = IHeaderMatchList(self._mlist)
+        header_matches.append('Subject', 'Bad', 'hold')
+        # This event subscriber records the event that occurs when the message
+        # is processed by the owner chain.
+        events = []
+        with event_subscribers(events.append):
+            process(self._mlist, msg, msgdata, start_chain='header-match')
+        self.assertEqual(len(events), 1)
+        event = events[0]
+        self.assertIsInstance(event, HoldEvent)
+        self.assertEqual(msgdata['moderation_reasons'],
+                         [('Header "{}" matched a header rule',
+                           'Bad subject')])
+
+    def test_reject_returns_reason(self):
+        # Test that a match with reject action returns a reason
+        msg = mfs("""\
+From: anne@example.com
+To: test@example.com
+Subject: Bad subject
+Message-ID: <ant>
+
+body
+
+""")
+        msgdata = {}
+        header_matches = IHeaderMatchList(self._mlist)
+        header_matches.append('Subject', 'Bad', 'reject')
+        # This event subscriber records the event that occurs when the message
+        # is processed by the owner chain.
+        events = []
+        with event_subscribers(events.append):
+            process(self._mlist, msg, msgdata, start_chain='header-match')
+        self.assertEqual(len(events), 1)
+        event = events[0]
+        self.assertIsInstance(event, RejectEvent)
+        self.assertEqual(msgdata['moderation_reasons'],
+                         [('Header "{}" matched a header rule',
+                           'Bad subject')])
diff --git a/src/mailman/chains/tests/test_hold.py b/src/mailman/chains/tests/test_hold.py
index b973b874c..560916e3b 100644
--- a/src/mailman/chains/tests/test_hold.py
+++ b/src/mailman/chains/tests/test_hold.py
@@ -111,6 +111,7 @@ A message body.
         msgdata = dict(moderation_reasons=[
             'TEST-REASON-1',
             'TEST-REASON-2',
+            ('TEST-{}-REASON-{}', 'FORMAT', 3),
             ])
         logfile = LogFileMark('mailman.vette')
         process_chain(self._mlist, msg, msgdata, start_chain='hold')
@@ -126,18 +127,22 @@ A message body.
                 self.fail('Unexpected message: %s' % item.msg)
         self.assertIn('    TEST-REASON-1', payloads['owner'])
         self.assertIn('    TEST-REASON-2', payloads['owner'])
+        self.assertIn('    TEST-FORMAT-REASON-3', payloads['owner'])
         self.assertIn('    TEST-REASON-1', payloads['sender'])
         self.assertIn('    TEST-REASON-2', payloads['sender'])
+        self.assertIn('    TEST-FORMAT-REASON-3', payloads['sender'])
         logged = logfile.read()
         self.assertIn('TEST-REASON-1', logged)
         self.assertIn('TEST-REASON-2', logged)
+        self.assertIn('TEST-FORMAT-REASON-3', logged)
         # Check the reason passed to hold_message().
         requests = IListRequests(self._mlist)
         self.assertEqual(requests.count_of(RequestType.held_message), 1)
         request = requests.of_type(RequestType.held_message)[0]
         key, data = requests.get_request(request.id)
         self.assertEqual(
-            data.get('_mod_reason'), 'TEST-REASON-1; TEST-REASON-2')
+            data.get('_mod_reason'),
+            'TEST-REASON-1; TEST-REASON-2; TEST-FORMAT-REASON-3')
 
     def test_hold_chain_no_reasons_given(self):
         msg = mfs("""\
diff --git a/src/mailman/chains/tests/test_reject.py b/src/mailman/chains/tests/test_reject.py
index f6fd6a8fe..8fce1de4a 100644
--- a/src/mailman/chains/tests/test_reject.py
+++ b/src/mailman/chains/tests/test_reject.py
@@ -45,12 +45,14 @@ Subject: Ignore
         msgdata = dict(moderation_reasons=[
             'TEST-REASON-1',
             'TEST-REASON-2',
+            ('TEST-{}-REASON-{}', 'FORMAT', 3),
             ])
         process_chain(self._mlist, self._msg, msgdata, start_chain='reject')
         bounces = get_queue_messages('virgin', expected_count=1)
         payload = bounces[0].msg.get_payload(0).as_string()
         self.assertIn('TEST-REASON-1', payload)
         self.assertIn('TEST-REASON-2', payload)
+        self.assertIn('TEST-FORMAT-REASON-3', payload)
 
     def test_no_reason(self):
         # There may be no moderation reasons.
diff --git a/src/mailman/docs/NEWS.rst b/src/mailman/docs/NEWS.rst
index f61233569..420e0fbe2 100644
--- a/src/mailman/docs/NEWS.rst
+++ b/src/mailman/docs/NEWS.rst
@@ -21,6 +21,8 @@ Bugs
   subject prefixing is fixed.  (Closes #359)
 * Messages with no syntactically valid senders are now automatically
   discarded.  (Closes #369)
+* Various message holds and rejects that gave 'N/A' as a reason now give an
+  appropriate reason.  (Closes #368)
 
 Command line
 ------------
diff --git a/src/mailman/rules/administrivia.py b/src/mailman/rules/administrivia.py
index d3d18d693..bd4602149 100644
--- a/src/mailman/rules/administrivia.py
+++ b/src/mailman/rules/administrivia.py
@@ -89,5 +89,10 @@ class Administrivia:
                 continue
             minargs, maxargs = EMAIL_COMMANDS[words[0]]
             if minargs <= len(words) - 1 <= maxargs:
+                msgdata['moderation_sender'] = msg.sender
+                with _.defer_translation():
+                    # This will be translated at the point of use.
+                    msgdata.setdefault('moderation_reasons', []).append(
+                        _('Message contains administrivia'))
                 return True
         return False
diff --git a/src/mailman/rules/banned_address.py b/src/mailman/rules/banned_address.py
index 77fb739a6..9fd011102 100644
--- a/src/mailman/rules/banned_address.py
+++ b/src/mailman/rules/banned_address.py
@@ -38,5 +38,11 @@ class BannedAddress:
         ban_manager = IBanManager(mlist)
         for sender in msg.senders:
             if ban_manager.is_banned(sender):
+                msgdata['moderation_sender'] = sender
+                with _.defer_translation():
+                    # This will be translated at the point of use.
+                    msgdata.setdefault('moderation_reasons', []).append(
+                        (_('Message sender {} is banned from this list'),
+                         sender))
                 return True
         return False
diff --git a/src/mailman/rules/dmarc.py b/src/mailman/rules/dmarc.py
index 90fff0855..9f9b11673 100644
--- a/src/mailman/rules/dmarc.py
+++ b/src/mailman/rules/dmarc.py
@@ -307,17 +307,23 @@ class DMARCMitigation:
             msgdata['dmarc'] = True
             if mlist.dmarc_mitigate_action is DMARCMitigateAction.discard:
                 msgdata['moderation_action'] = 'discard'
-                msgdata['moderation_reasons'] = [_('DMARC moderation')]
+                with _.defer_translation():
+                    # This will be translated at the point of use.
+                    msgdata.setdefault('moderation_reasons', []).append(
+                        _('DMARC moderation'))
             elif mlist.dmarc_mitigate_action is DMARCMitigateAction.reject:
                 listowner = mlist.owner_address       # noqa F841
-                reason = (mlist.dmarc_moderation_notice or
-                          _('You are not allowed to post to this mailing '
-                            'list From: a domain which publishes a DMARC '
-                            'policy of reject or quarantine, and your message'
-                            ' has been automatically rejected.  If you think '
-                            'that your messages are being rejected in error, '
-                            'contact the mailing list owner at ${listowner}.'))
-                msgdata['moderation_reasons'] = [wrap(reason)]
+                with _.defer_translation():
+                    # This will be translated at the point of use.
+                    reason = (mlist.dmarc_moderation_notice or _(
+                        'You are not allowed to post to this mailing '
+                        'list From: a domain which publishes a DMARC '
+                        'policy of reject or quarantine, and your message'
+                        ' has been automatically rejected.  If you think '
+                        'that your messages are being rejected in error, '
+                        'contact the mailing list owner at ${listowner}.'))
+                msgdata.setdefault('moderation_reasons', []).append(
+                    wrap(reason))
                 msgdata['moderation_action'] = 'reject'
             else:
                 return False
diff --git a/src/mailman/rules/emergency.py b/src/mailman/rules/emergency.py
index ac512f391..3f8da002b 100644
--- a/src/mailman/rules/emergency.py
+++ b/src/mailman/rules/emergency.py
@@ -39,4 +39,11 @@ class Emergency:
 
     def check(self, mlist, msg, msgdata):
         """See `IRule`."""
-        return mlist.emergency and not msgdata.get('moderator_approved')
+        if mlist.emergency and not msgdata.get('moderator_approved'):
+            msgdata['moderation_sender'] = msg.sender
+            with _.defer_translation():
+                # This will be translated at the point of use.
+                msgdata.setdefault('moderation_reasons', []).append(
+                    _('Emergency moderation is in effect for this list'))
+            return True
+        return False
diff --git a/src/mailman/rules/implicit_dest.py b/src/mailman/rules/implicit_dest.py
index 7e6658d49..26729a86e 100644
--- a/src/mailman/rules/implicit_dest.py
+++ b/src/mailman/rules/implicit_dest.py
@@ -88,4 +88,9 @@ class ImplicitDestination:
                         if re.match(escaped, recipient, re.IGNORECASE):
                             return False
         # Nothing matched.
+        msgdata['moderation_sender'] = msg.sender
+        with _.defer_translation():
+            # This will be translated at the point of use.
+            msgdata.setdefault('moderation_reasons', []).append(
+                _('Message has implicit destination'))
         return True
diff --git a/src/mailman/rules/loop.py b/src/mailman/rules/loop.py
index ac4d00461..b50b55ed6 100644
--- a/src/mailman/rules/loop.py
+++ b/src/mailman/rules/loop.py
@@ -37,4 +37,11 @@ class Loop:
         # Has this message already been posted to this list?
         list_posts = set(value.strip().lower()
                          for value in msg.get_all('list-post', []))
-        return mlist.posting_address in list_posts
+        if mlist.posting_address in list_posts:
+            msgdata['moderation_sender'] = msg.sender
+            with _.defer_translation():
+                # This will be translated at the point of use.
+                msgdata.setdefault('moderation_reasons', []).append(
+                    _('Message has already been posted to this list'))
+            return True
+        return False
diff --git a/src/mailman/rules/max_recipients.py b/src/mailman/rules/max_recipients.py
index 1f95f71cc..8a90fd451 100644
--- a/src/mailman/rules/max_recipients.py
+++ b/src/mailman/rules/max_recipients.py
@@ -41,4 +41,12 @@ class MaximumRecipients:
         # Figure out how many recipients there are
         recipients = getaddresses(msg.get_all('to', []) +
                                   msg.get_all('cc', []))
-        return len(recipients) >= mlist.max_num_recipients
+        if len(recipients) >= mlist.max_num_recipients:
+            msgdata['moderation_sender'] = msg.sender
+            with _.defer_translation():
+                # This will be translated at the point of use.
+                msgdata.setdefault('moderation_reasons', []).append(
+                    (_('Message has more than {} recipients'),
+                     mlist.max_num_recipients))
+            return True
+        return False
diff --git a/src/mailman/rules/max_size.py b/src/mailman/rules/max_size.py
index 46c8fc5ac..2554e0db0 100644
--- a/src/mailman/rules/max_size.py
+++ b/src/mailman/rules/max_size.py
@@ -39,4 +39,12 @@ class MaximumSize:
         assert hasattr(msg, 'original_size'), (
             'Message was not sized on initial parsing.')
         # The maximum size is specified in 1024 bytes.
-        return msg.original_size / 1024.0 > mlist.max_message_size
+        if msg.original_size / 1024.0 > mlist.max_message_size:
+            msgdata['moderation_sender'] = msg.sender
+            with _.defer_translation():
+                # This will be translated at the point of use.
+                msgdata.setdefault('moderation_reasons', []).append(
+                    (_('The message is larger than the {} KB maximum size'),
+                     mlist.max_message_size))
+            return True
+        return False
diff --git a/src/mailman/rules/moderation.py b/src/mailman/rules/moderation.py
index 322216fb8..7f78d3ce7 100644
--- a/src/mailman/rules/moderation.py
+++ b/src/mailman/rules/moderation.py
@@ -84,9 +84,10 @@ class MemberModeration:
             # stored in the pending request table.
             msgdata['moderation_action'] = action.name
             msgdata['moderation_sender'] = sender
-            msgdata.setdefault('moderation_reasons', []).append(
-                # This will get translated at the point of use.
-                'The message comes from a moderated member')
+            with _.defer_translation():
+                # This will be translated at the point of use.
+                msgdata.setdefault('moderation_reasons', []).append(
+                    _('The message comes from a moderated member'))
             return True
         # The sender is not a member so this rule does not match.
         return False
@@ -146,10 +147,12 @@ class NonmemberModeration:
                 for addr in checklist:
                     if ((addr.startswith('^') and re.match(addr, sender))
                             or addr == sender):     # noqa: W503
-                        # The reason will get translated at the point of use.
-                        reason = 'The sender is in the nonmember {} list'
-                        _record_action(msgdata, action, sender,
-                                       reason.format(action))
+                        with _.defer_translation():
+                            # This will be translated at the point of use.
+                            reason = (
+                                _('The sender is in the nonmember {} list'),
+                                action)
+                        _record_action(msgdata, action, sender, reason)
                         return True
             action = (mlist.default_nonmember_action
                       if nonmember.moderation_action is None
@@ -160,9 +163,9 @@ class NonmemberModeration:
             elif action is not None:
                 # We must stringify the moderation action so that it can be
                 # stored in the pending request table.
-                #
-                # The reason will get translated at the point of use.
-                reason = 'The message is not from a list member'
+                with _.defer_translation():
+                    # This will be translated at the point of use.
+                    reason = _('The message is not from a list member')
                 _record_action(msgdata, action.name, sender, reason)
                 return True
         # The sender must be a member, so this rule does not match.
diff --git a/src/mailman/rules/news_moderation.py b/src/mailman/rules/news_moderation.py
index a606197f0..3d3d39dc6 100644
--- a/src/mailman/rules/news_moderation.py
+++ b/src/mailman/rules/news_moderation.py
@@ -38,4 +38,11 @@ class ModeratedNewsgroup:
 
     def check(self, mlist, msg, msgdata):
         """See `IRule`."""
-        return mlist.newsgroup_moderation == NewsgroupModeration.moderated
+        if mlist.newsgroup_moderation is NewsgroupModeration.moderated:
+            msgdata['moderation_sender'] = msg.sender
+            with _.defer_translation():
+                # This will be translated at the point of use.
+                msgdata.setdefault('moderation_reasons', []).append(
+                    _('Post to a moderated newsgroup gateway'))
+            return True
+        return False
diff --git a/src/mailman/rules/no_senders.py b/src/mailman/rules/no_senders.py
index 7e8c78fa7..24e5fa5bd 100644
--- a/src/mailman/rules/no_senders.py
+++ b/src/mailman/rules/no_senders.py
@@ -37,9 +37,9 @@ class NoSenders:
         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')
+            msgdata['moderation_sender'] = 'N/A'
+            with _.defer_translation():
+                # This will be translated at the point of use.
+                msgdata.setdefault('moderation_reasons', []).append(
+                    _('The message has no valid senders'))
             return True
diff --git a/src/mailman/rules/no_subject.py b/src/mailman/rules/no_subject.py
index f4d2f6a5d..9793ca2a5 100644
--- a/src/mailman/rules/no_subject.py
+++ b/src/mailman/rules/no_subject.py
@@ -37,4 +37,11 @@ class NoSubject:
         # Convert the header value to a str because it may be an
         # email.header.Header instance.
         subject = str(msg.get('subject', '')).strip()
-        return subject == ''
+        if subject == '':
+            msgdata['moderation_sender'] = msg.sender
+            with _.defer_translation():
+                # This will be translated at the point of use.
+                msgdata.setdefault('moderation_reasons', []).append(
+                    _('Message has no subject'))
+            return True
+        return False
diff --git a/src/mailman/rules/suspicious.py b/src/mailman/rules/suspicious.py
index 9f0f0e922..1bf96d22a 100644
--- a/src/mailman/rules/suspicious.py
+++ b/src/mailman/rules/suspicious.py
@@ -41,7 +41,7 @@ class SuspiciousHeader:
     def check(self, mlist, msg, msgdata):
         """See `IRule`."""
         return (mlist.bounce_matching_headers and
-                has_matching_bounce_header(mlist, msg))
+                has_matching_bounce_header(mlist, msg, msgdata))
 
 
 def _parse_matching_header_opt(mlist):
@@ -77,7 +77,7 @@ bad regexp in bounce_matching_header line: %s
     return all
 
 
-def has_matching_bounce_header(mlist, msg):
+def has_matching_bounce_header(mlist, msg, msgdata):
     """Does the message have a matching bounce header?
 
     :param mlist: The mailing list the message is destined for.
@@ -90,5 +90,11 @@ def has_matching_bounce_header(mlist, msg):
             # Convert the header value to a str because it may be an
             # email.header.Header instance.
             if cre.search(str(value)):
+                msgdata['moderation_sender'] = msg.sender
+                with _.defer_translation():
+                    # This will be translated at the point of use.
+                    msgdata.setdefault('moderation_reasons', []).append((_(
+                        'Header "{}" matched a bounce_matching_header line'),
+                        str(value)))
                 return True
     return False
diff --git a/src/mailman/rules/tests/test_administrivia.py b/src/mailman/rules/tests/test_administrivia.py
new file mode 100644
index 000000000..e370a0bf2
--- /dev/null
+++ b/src/mailman/rules/tests/test_administrivia.py
@@ -0,0 +1,51 @@
+# 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 `administrivia` rule."""
+
+import unittest
+
+from mailman.app.lifecycle import create_list
+from mailman.rules import administrivia
+from mailman.testing.helpers import specialized_message_from_string as mfs
+from mailman.testing.layers import ConfigLayer
+
+
+class TestAdministrivia(unittest.TestCase):
+    """Test the administrivia rule."""
+
+    layer = ConfigLayer
+
+    def setUp(self):
+        self._mlist = create_list('test@example.com')
+
+    def test_administrivia_returns_reason(self):
+        # Ensure administrivia rule returns a reason.
+        msg = mfs("""\
+From: anne@example.com
+To: test@example.com
+Subject: unsubscribe
+Message-ID: <ant>
+
+A message body.
+""")
+        rule = administrivia.Administrivia()
+        msgdata = {}
+        result = rule.check(self._mlist, msg, msgdata)
+        self.assertTrue(result)
+        self.assertEqual(msgdata['moderation_reasons'],
+                         ['Message contains administrivia'])
diff --git a/src/mailman/rules/tests/test_banned_address.py b/src/mailman/rules/tests/test_banned_address.py
index 1ecab5b18..2d73ed3fb 100644
--- a/src/mailman/rules/tests/test_banned_address.py
+++ b/src/mailman/rules/tests/test_banned_address.py
@@ -74,6 +74,30 @@ A message body.
         result = rule.check(self._mlist, msg, {})
         self.assertTrue(result)
 
+    def test_rule_returns_reason(self):
+        # Ensure a reason is returned.
+        user_manager = getUtility(IUserManager)
+        anne = user_manager.create_user('anne@example.com')
+        set_preferred(anne)
+        IBanManager(self._mlist).ban('anne@example.com')
+        msg = mfs("""\
+From: anne@example.com
+To: test@example.com
+Subject: A test message
+Message-ID: <ant>
+MIME-Version: 1.0
+
+A message body.
+""")
+        rule = banned_address.BannedAddress()
+        msgdata = {}
+        result = rule.check(self._mlist, msg, msgdata)
+        self.assertTrue(result)
+        self.assertEqual(
+            msgdata['moderation_reasons'],
+            [('Message sender {} is banned from this list',
+              'anne@example.com')])
+
     def test_banned_address_linked_to_user(self):
         # Anne is subscribed to a mailing list as a user with her preferred
         # address.  She also has a secondary address which is banned and which
diff --git a/src/mailman/rules/tests/test_emergency.py b/src/mailman/rules/tests/test_emergency.py
new file mode 100644
index 000000000..529742987
--- /dev/null
+++ b/src/mailman/rules/tests/test_emergency.py
@@ -0,0 +1,52 @@
+# 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 `emergency` rule."""
+
+import unittest
+
+from mailman.app.lifecycle import create_list
+from mailman.rules import emergency
+from mailman.testing.helpers import specialized_message_from_string as mfs
+from mailman.testing.layers import ConfigLayer
+
+
+class TestEmergency(unittest.TestCase):
+    """Test the emergency rule."""
+
+    layer = ConfigLayer
+
+    def setUp(self):
+        self._mlist = create_list('test@example.com')
+
+    def test_emergency_returns_reason(self):
+        # Ensure emergency rule returns a reason.
+        msg = mfs("""\
+From: anne@example.com
+To: test@example.com
+Subject: A Subject
+Message-ID: <ant>
+
+A message body.
+""")
+        rule = emergency.Emergency()
+        self._mlist.emergency = True
+        msgdata = {}
+        result = rule.check(self._mlist, msg, msgdata)
+        self.assertTrue(result)
+        self.assertEqual(msgdata['moderation_reasons'],
+                         ['Emergency moderation is in effect for this list'])
diff --git a/src/mailman/rules/tests/test_implicit_dest.py b/src/mailman/rules/tests/test_implicit_dest.py
new file mode 100644
index 000000000..aed317f57
--- /dev/null
+++ b/src/mailman/rules/tests/test_implicit_dest.py
@@ -0,0 +1,51 @@
+# 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 `implicit_dest` rule."""
+
+import unittest
+
+from mailman.app.lifecycle import create_list
+from mailman.rules import implicit_dest
+from mailman.testing.helpers import specialized_message_from_string as mfs
+from mailman.testing.layers import ConfigLayer
+
+
+class TestImplicitDestination(unittest.TestCase):
+    """Test the implicit_dest rule."""
+
+    layer = ConfigLayer
+
+    def setUp(self):
+        self._mlist = create_list('test@example.com')
+
+    def test_implicit_dest_returns_reason(self):
+        # Ensure implicit_dest rule returns a reason.
+        msg = mfs("""\
+From: anne@example.com
+To: bogus@example.com
+Subject: A Subject
+Message-ID: <ant>
+
+A message body.
+""")
+        rule = implicit_dest.ImplicitDestination()
+        msgdata = {}
+        result = rule.check(self._mlist, msg, msgdata)
+        self.assertTrue(result)
+        self.assertEqual(msgdata['moderation_reasons'],
+                         ['Message has implicit destination'])
diff --git a/src/mailman/rules/tests/test_loop.py b/src/mailman/rules/tests/test_loop.py
new file mode 100644
index 000000000..09f9fc905
--- /dev/null
+++ b/src/mailman/rules/tests/test_loop.py
@@ -0,0 +1,52 @@
+# 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 `loop` rule."""
+
+import unittest
+
+from mailman.app.lifecycle import create_list
+from mailman.rules import loop
+from mailman.testing.helpers import specialized_message_from_string as mfs
+from mailman.testing.layers import ConfigLayer
+
+
+class TestLoop(unittest.TestCase):
+    """Test the loop rule."""
+
+    layer = ConfigLayer
+
+    def setUp(self):
+        self._mlist = create_list('test@example.com')
+
+    def test_loop_returns_reason(self):
+        # Ensure loop rule returns a reason.
+        msg = mfs("""\
+From: anne@example.com
+To: test@example.com
+Subject: A Subject
+List-Post: test@example.com
+Message-ID: <ant>
+
+A message body.
+""")
+        rule = loop.Loop()
+        msgdata = {}
+        result = rule.check(self._mlist, msg, msgdata)
+        self.assertTrue(result)
+        self.assertEqual(msgdata['moderation_reasons'],
+                         ['Message has already been posted to this list'])
diff --git a/src/mailman/rules/tests/test_max_recipients.py b/src/mailman/rules/tests/test_max_recipients.py
new file mode 100644
index 000000000..08663f1e5
--- /dev/null
+++ b/src/mailman/rules/tests/test_max_recipients.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 `max_recipients` rule."""
+
+import unittest
+
+from mailman.app.lifecycle import create_list
+from mailman.rules import max_recipients
+from mailman.testing.helpers import specialized_message_from_string as mfs
+from mailman.testing.layers import ConfigLayer
+
+
+class TestMaximumRecipients(unittest.TestCase):
+    """Test the max_recipients rule."""
+
+    layer = ConfigLayer
+
+    def setUp(self):
+        self._mlist = create_list('test@example.com')
+
+    def test_max_recipients_returns_reason(self):
+        # Ensure max_recipients rule returns a reason.
+        msg = mfs("""\
+From: anne@example.com
+To: test@example.com
+Cc: anne@example.com, bill@example.com
+Subject: A Subject
+Message-ID: <ant>
+
+A message body.
+""")
+        rule = max_recipients.MaximumRecipients()
+        self._mlist.max_num_recipients = 2
+        msgdata = {}
+        result = rule.check(self._mlist, msg, msgdata)
+        self.assertTrue(result)
+        self.assertEqual(msgdata['moderation_reasons'],
+                         [('Message has more than {} recipients', 2)])
diff --git a/src/mailman/rules/tests/test_max_size.py b/src/mailman/rules/tests/test_max_size.py
new file mode 100644
index 000000000..56b279a6b
--- /dev/null
+++ b/src/mailman/rules/tests/test_max_size.py
@@ -0,0 +1,55 @@
+# 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 `max_size` rule."""
+
+import unittest
+
+from mailman.app.lifecycle import create_list
+from mailman.rules import max_size
+from mailman.testing.helpers import specialized_message_from_string as mfs
+from mailman.testing.layers import ConfigLayer
+
+
+class TestMaximumSize(unittest.TestCase):
+    """Test the max_size rule."""
+
+    layer = ConfigLayer
+
+    def setUp(self):
+        self._mlist = create_list('test@example.com')
+
+    def test_max_size_returns_reason(self):
+        # Ensure max_size rule returns a reason.
+        msg = mfs("""\
+From: anne@example.com
+To: test@example.com
+Subject: A Subject
+Message-ID: <ant>
+
+A message body.
+""")
+        rule = max_size.MaximumSize()
+        self._mlist.max_message_size = 1
+        # Fake the size.
+        msg.original_size = 2048
+        msgdata = {}
+        result = rule.check(self._mlist, msg, msgdata)
+        self.assertTrue(result)
+        self.assertEqual(msgdata['moderation_reasons'],
+                         [('The message is larger than the {} KB maximum size',
+                          1)])
diff --git a/src/mailman/rules/tests/test_news_moderation.py b/src/mailman/rules/tests/test_news_moderation.py
new file mode 100644
index 000000000..aec9e2b14
--- /dev/null
+++ b/src/mailman/rules/tests/test_news_moderation.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 `news_moderation` rule."""
+
+import unittest
+
+from mailman.app.lifecycle import create_list
+from mailman.interfaces.nntp import NewsgroupModeration
+from mailman.rules import news_moderation
+from mailman.testing.helpers import specialized_message_from_string as mfs
+from mailman.testing.layers import ConfigLayer
+
+
+class TestModeratedNewsgroup(unittest.TestCase):
+    """Test the news_moderation rule."""
+
+    layer = ConfigLayer
+
+    def setUp(self):
+        self._mlist = create_list('test@example.com')
+
+    def test_news_moderation_returns_reason(self):
+        # Ensure news_moderation rule returns a reason.
+        msg = mfs("""\
+From: anne@example.com
+To: test@example.com
+Subject: A Subject
+Message-ID: <ant>
+
+A message body.
+""")
+        rule = news_moderation.ModeratedNewsgroup()
+        self._mlist.newsgroup_moderation = NewsgroupModeration.moderated
+        msgdata = {}
+        result = rule.check(self._mlist, msg, msgdata)
+        self.assertTrue(result)
+        self.assertEqual(msgdata['moderation_reasons'],
+                         ['Post to a moderated newsgroup gateway'])
diff --git a/src/mailman/rules/tests/test_no_senders.py b/src/mailman/rules/tests/test_no_senders.py
index eb59dfe71..06bda5360 100644
--- a/src/mailman/rules/tests/test_no_senders.py
+++ b/src/mailman/rules/tests/test_no_senders.py
@@ -25,7 +25,7 @@ from mailman.rules import no_senders
 from mailman.testing.layers import ConfigLayer
 
 
-class TestNoSubject(unittest.TestCase):
+class TestNoSender(unittest.TestCase):
     """Test the no_senders rule."""
 
     layer = ConfigLayer
@@ -39,10 +39,9 @@ class TestNoSubject(unittest.TestCase):
         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')
+        self.assertEqual(msgdata['moderation_sender'], 'N/A')
 
     def test_message_has_sender(self):
         msg = Message()
diff --git a/src/mailman/rules/tests/test_no_subject.py b/src/mailman/rules/tests/test_no_subject.py
index 0379ea689..e80e2e4eb 100644
--- a/src/mailman/rules/tests/test_no_subject.py
+++ b/src/mailman/rules/tests/test_no_subject.py
@@ -46,3 +46,12 @@ class TestNoSubject(unittest.TestCase):
         msg['Subject'] = Header('Test subject')
         result = self._rule.check(self._mlist, msg, {})
         self.assertFalse(result)
+
+    def test_no_subject_returns_reason(self):
+        msg = Message()
+        msg['Subject'] = Header('')
+        msgdata = {}
+        result = self._rule.check(self._mlist, msg, msgdata)
+        self.assertTrue(result)
+        self.assertEqual(msgdata['moderation_reasons'],
+                         ['Message has no subject'])
diff --git a/src/mailman/rules/tests/test_suspicious.py b/src/mailman/rules/tests/test_suspicious.py
index b40292283..4012c89d5 100644
--- a/src/mailman/rules/tests/test_suspicious.py
+++ b/src/mailman/rules/tests/test_suspicious.py
@@ -42,3 +42,16 @@ class TestSuspicious(unittest.TestCase):
         self._mlist.bounce_matching_headers = 'from: spam@example.com'
         result = self._rule.check(self._mlist, msg, {})
         self.assertFalse(result)
+
+    def test_suspicious_returns_reason(self):
+        msg = Message()
+        msg['From'] = Header('spam@example.com')
+        self._mlist.bounce_matching_headers = 'from: spam@example.com'
+        msgdata = {}
+        result = self._rule.check(self._mlist, msg, msgdata)
+        self.assertTrue(result)
+        self.assertEqual(
+            msgdata['moderation_reasons'],
+            [('Header "{}" matched a bounce_matching_header line',
+              'spam@example.com')]
+            )