Merge branch 'rename-metadata-key' into 'master'

Rename metadata key for clarity
Compose bounce messages so that they can be properly translated

See merge request !304

27 files changed, 355 insertions, 115 deletions

diff --git a/src/mailman/app/bounces.py b/src/mailman/app/bounces.py
index 1239c916c..0d9a6ccb9 100644
--- a/src/mailman/app/bounces.py
+++ b/src/mailman/app/bounces.py
@@ -45,6 +45,7 @@ elog = logging.getLogger('mailman.error')
 blog = logging.getLogger('mailman.bounce')
 
 DOT = '.'
+NL = '\n'
 
 
 @public
@@ -56,8 +57,12 @@ def bounce_message(mlist, msg, error=None):
     :param msg: The original message.
     :type msg: `email.message.Message`
     :param error: Optional exception causing the bounce.  The exception
-        instance must have a `.message` attribute.
-    :type error: Exception
+        instance must have a `.message` attribute.  The exception *may* have a
+        non-None `.reasons` attribute which would be a list of reasons for the
+        rejection, and it may have a non-None `.substitutions` attribute.  The
+        latter, along with the formatted reasons will be interpolated into the
+        message (`.reasons` gets put into the `$reasons` placeholder).
+    :type error: RejectMessage
     """
     # Bounce a message back to the sender, with an error message if provided
     # in the exception argument.  .sender might be None or the empty string.
@@ -67,10 +72,9 @@ def bounce_message(mlist, msg, error=None):
         return
     subject = msg.get('subject', _('(no subject)'))
     subject = oneline(subject, mlist.preferred_language.charset)
-    if error is None:
-        notice = _('[No bounce details are available]')
-    else:
-        notice = _(error.message)
+    notice = (_('[No bounce details are available]')
+              if error is None
+              else str(error))
     # Currently we always craft bounces as MIME messages.
     bmsg = UserNotification(msg.sender, mlist.owner_address, subject,
                             lang=mlist.preferred_language)
diff --git a/src/mailman/app/docs/bounces.rst b/src/mailman/app/docs/bounces.rst
index 99eae8b2c..b25381031 100644
--- a/src/mailman/app/docs/bounces.rst
+++ b/src/mailman/app/docs/bounces.rst
@@ -12,12 +12,12 @@ Mailman can bounce messages back to the original sender.  This is essentially
 equivalent to rejecting the message with notification.  Mailing lists can
 bounce a message with an optional error message.
 
-    >>> mlist = create_list('text@example.com')
+    >>> mlist = create_list('ant@example.com')
 
 Any message can be bounced.
 
     >>> msg = message_from_string("""\
-    ... To: text@example.com
+    ... To: ant@example.com
     ... From: aperson@example.com
     ... Subject: Something important
     ...
@@ -36,7 +36,7 @@ to the original message author.
     1
     >>> print(items[0].msg.as_string())
     Subject: Something important
-    From: text-owner@example.com
+    From: ant-owner@example.com
     To: aperson@example.com
     MIME-Version: 1.0
     Content-Type: multipart/mixed; boundary="..."
@@ -54,7 +54,7 @@ to the original message author.
     Content-Type: message/rfc822
     MIME-Version: 1.0
     <BLANKLINE>
-    To: text@example.com
+    To: ant@example.com
     From: aperson@example.com
     Subject: Something important
     <BLANKLINE>
@@ -63,18 +63,16 @@ to the original message author.
     --...--
 
 An error message can be given when the message is bounced, and this will be
-included in the payload of the text/plain part.  The error message must be
+included in the payload of the ``text/plain`` part.  The error message must be
 passed in as an instance of a ``RejectMessage`` exception.
 
     >>> from mailman.interfaces.pipeline import RejectMessage
     >>> error = RejectMessage("This wasn't very important after all.")
     >>> bounce_message(mlist, msg, error)
-    >>> items = get_queue_messages('virgin')
-    >>> len(items)
-    1
+    >>> items = get_queue_messages('virgin', expected_count=1)
     >>> print(items[0].msg.as_string())
     Subject: Something important
-    From: text-owner@example.com
+    From: ant-owner@example.com
     To: aperson@example.com
     MIME-Version: 1.0
     Content-Type: multipart/mixed; boundary="..."
@@ -92,10 +90,56 @@ passed in as an instance of a ``RejectMessage`` exception.
     Content-Type: message/rfc822
     MIME-Version: 1.0
     <BLANKLINE>
-    To: text@example.com
+    To: ant@example.com
     From: aperson@example.com
     Subject: Something important
     <BLANKLINE>
     I sometimes say something important.
     <BLANKLINE>
     --...--
+
+The ``RejectMessage`` exception can also include a set of reasons, which will
+be interpolated into the message using the ``{reasons}`` placeholder.
+
+    >>> error = RejectMessage("""This message is rejected because:
+    ...
+    ... $reasons
+    ... """, [
+    ...     'I am not happy',
+    ...     'You are not happy',
+    ...     'We are not happy'])
+    >>> bounce_message(mlist, msg, error)
+    >>> items = get_queue_messages('virgin', expected_count=1)
+    >>> print(items[0].msg.as_string())
+    Subject: Something important
+    From: ant-owner@example.com
+    To: aperson@example.com
+    MIME-Version: 1.0
+    Content-Type: multipart/mixed; boundary="..."
+    Message-ID: ...
+    Date: ...
+    Precedence: bulk
+    <BLANKLINE>
+    --...
+    Content-Type: text/plain; charset="us-ascii"
+    MIME-Version: 1.0
+    Content-Transfer-Encoding: 7bit
+    <BLANKLINE>
+    This message is rejected because:
+    <BLANKLINE>
+    I am not happy
+    You are not happy
+    We are not happy
+    <BLANKLINE>
+    --...
+    Content-Type: message/rfc822
+    MIME-Version: 1.0
+    <BLANKLINE>
+    To: ant@example.com
+    From: aperson@example.com
+    Subject: Something important
+    <BLANKLINE>
+    I sometimes say something important.
+    <BLANKLINE>
+    --...
+    <BLANKLINE>
diff --git a/src/mailman/chains/base.py b/src/mailman/chains/base.py
index 9507d8fbc..45301abc3 100644
--- a/src/mailman/chains/base.py
+++ b/src/mailman/chains/base.py
@@ -18,7 +18,6 @@
 """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
@@ -28,24 +27,6 @@ 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."""
@@ -107,6 +88,31 @@ class TerminalChainBase:
 
 @public
 @abstract_component
+@implementer(IChain)
+class JumpChainBase:
+    """A base chain that simplifies jumping to another chain."""
+    def jump_to(self, mlist, msg, msgsdata):
+        """Return the chain to jump to.
+
+        This must be overridden by subclasses.
+
+        :param mlist: The mailing list.
+        :param msg: The message.
+        :param msgdata: The message metadata.
+        :return: The name of the chain to jump to.
+        :rtype: str
+        """
+        raise NotImplementedError
+
+    def get_links(self, mlist, msg, msgdata):
+        jump_chain = self.jump_to(mlist, msg, msgdata)
+        return iter([
+            Link('truth', LinkAction.jump, jump_chain),
+            ])
+
+
+@public
+@abstract_component
 @implementer(IMutableChain)
 class Chain:
     """Generic chain base class."""
diff --git a/src/mailman/chains/builtin.py b/src/mailman/chains/builtin.py
index 9b97fef38..ad016201f 100644
--- a/src/mailman/chains/builtin.py
+++ b/src/mailman/chains/builtin.py
@@ -41,7 +41,7 @@ class BuiltInChain:
         # First check DMARC.  For a reject or discard, the rule hits and we
         # jump to the moderation chain to do the action.  Otherwise, the rule
         # misses buts sets msgdata['dmarc'] for the handler.
-        ('dmarc-mitigation', LinkAction.jump, 'moderation'),
+        ('dmarc-mitigation', LinkAction.jump, 'dmarc'),
         # Discard emails with no valid senders.
         ('no-senders', LinkAction.jump, 'discard'),
         ('approved', LinkAction.jump, 'accept'),
diff --git a/src/mailman/chains/dmarc.py b/src/mailman/chains/dmarc.py
new file mode 100644
index 000000000..6a8d4d188
--- /dev/null
+++ b/src/mailman/chains/dmarc.py
@@ -0,0 +1,39 @@
+# Copyright (C) 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/>.
+
+"""DMARC mitigation chain."""
+
+from mailman.chains.base import JumpChainBase
+from mailman.core.i18n import _
+from public import public
+
+
+@public
+class DMARCMitigationChain(JumpChainBase):
+    """Perform DMARC mitigation."""
+
+    name = 'dmarc'
+    description = _('Process DMARC reject or discard mitigations')
+
+    def jump_to(self, mlist, msg, msgdata):
+        # Which action should be taken?
+        jump_chain = msgdata['dmarc_action']
+        assert jump_chain in ('discard', 'reject'), (
+            '{}: Invalid DMARC action: {} for sender: {}'.format(
+                mlist.list_id, jump_chain,
+                msgdata.get('moderation_sender', '(unknown)')))
+        return jump_chain
diff --git a/src/mailman/chains/hold.py b/src/mailman/chains/hold.py
index edc80da3c..ea25dbc0d 100644
--- a/src/mailman/chains/hold.py
+++ b/src/mailman/chains/hold.py
@@ -24,9 +24,9 @@ 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, format_reasons
+from mailman.chains.base import TerminalChainBase
 from mailman.config import config
-from mailman.core.i18n import _
+from mailman.core.i18n import _, format_reasons
 from mailman.email.message import UserNotification
 from mailman.interfaces.autorespond import IAutoResponseSet, Response
 from mailman.interfaces.chain import HoldEvent
diff --git a/src/mailman/chains/moderation.py b/src/mailman/chains/moderation.py
index 7cfc0a01e..d8f8fb7e7 100644
--- a/src/mailman/chains/moderation.py
+++ b/src/mailman/chains/moderation.py
@@ -34,17 +34,14 @@ made as to the disposition of the message.  `defer` is the default for
 members, while `hold` is the default for nonmembers.
 """
 
-from mailman.chains.base import Link
+from mailman.chains.base import JumpChainBase
 from mailman.core.i18n import _
 from mailman.interfaces.action import Action
-from mailman.interfaces.chain import IChain, LinkAction
 from public import public
-from zope.interface import implementer
 
 
 @public
-@implementer(IChain)
-class ModerationChain:
+class ModerationChain(JumpChainBase):
     """Dynamically produce a link jumping to the appropriate terminal chain.
 
     The terminal chain will be one of the Accept, Hold, Discard, or Reject
@@ -53,13 +50,12 @@ class ModerationChain:
     name = 'moderation'
     description = _('Moderation chain')
 
-    def get_links(self, mlist, msg, msgdata):
-        """See `IChain`."""
+    def jump_to(self, mlist, msg, msgdata):
         # Get the moderation action from the message metadata.  It can only be
         # one of the expected values (i.e. not Action.defer).  See the
         # moderation.py rule for details.  This is stored in the metadata as a
         # string so that it can be stored in the pending table.
-        action = Action[msgdata.get('moderation_action')]
+        action = Action[msgdata.get('member_moderation_action')]
         # defer is not a valid moderation action.
         jump_chain = {
             Action.accept: 'accept',
@@ -68,9 +64,7 @@ class ModerationChain:
             Action.reject: 'reject',
             }.get(action)
         assert jump_chain is not None, (
-            '{0}: Invalid moderation action: {1} for sender: {2}'.format(
-                mlist.fqdn_listname, action,
+            '{}: Invalid moderation action: {} for sender: {}'.format(
+                mlist.list_id, action,
                 msgdata.get('moderation_sender', '(unknown)')))
-        return iter([
-            Link('truth', LinkAction.jump, jump_chain),
-            ])
+        return jump_chain
diff --git a/src/mailman/chains/reject.py b/src/mailman/chains/reject.py
index 31f66c8fa..6696e1900 100644
--- a/src/mailman/chains/reject.py
+++ b/src/mailman/chains/reject.py
@@ -20,11 +20,13 @@
 import logging
 
 from mailman.app.bounces import bounce_message
-from mailman.chains.base import TerminalChainBase, format_reasons
+from mailman.chains.base import TerminalChainBase
 from mailman.core.i18n import _
 from mailman.interfaces.chain import RejectEvent
 from mailman.interfaces.pipeline import RejectMessage
+from mailman.interfaces.template import ITemplateLoader
 from public import public
+from zope.component import getUtility
 from zope.event import notify
 
 
@@ -56,17 +58,10 @@ class RejectChain(TerminalChainBase):
         if reasons is None:
             error = None
         else:
-            error = RejectMessage(_("""
-Your message to the {list_name} mailing-list was rejected for the following
-reasons:
-
-{reasons}
-
-The original message as received by Mailman is attached.
-""").format(
-    list_name=mlist.display_name,                   # noqa: E122
-    reasons=NEWLINE.join(format_reasons(reasons))
-    ))
+            template = getUtility(ITemplateLoader).get(
+                'list:user:notice:rejected', mlist)
+            error = RejectMessage(
+                template, reasons, dict(listname=mlist.display_name))
         bounce_message(mlist, msg, error)
         log.info('REJECT: %s', msg.get('message-id', 'n/a'))
         notify(RejectEvent(mlist, msg, msgdata, self))
diff --git a/src/mailman/chains/tests/test_accept.py b/src/mailman/chains/tests/test_accept.py
index 65b18d0b4..bf8bad541 100644
--- a/src/mailman/chains/tests/test_accept.py
+++ b/src/mailman/chains/tests/test_accept.py
@@ -51,7 +51,7 @@ class TestAccept(unittest.TestCase):
         self._mlist = create_list('ant@example.com')
         self._msg = mfs("""\
 From: anne@example.com
-To: test@example.com
+To: ant@example.com
 Subject: Ignore
 
 """)
diff --git a/src/mailman/chains/tests/test_dmarc.py b/src/mailman/chains/tests/test_dmarc.py
new file mode 100644
index 000000000..8d0072254
--- /dev/null
+++ b/src/mailman/chains/tests/test_dmarc.py
@@ -0,0 +1,82 @@
+# Copyright (C) 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 for the DMARC chain."""
+
+import unittest
+
+from mailman.app.lifecycle import create_list
+from mailman.core.chains import process as process_chain
+from mailman.interfaces.chain import DiscardEvent, RejectEvent
+from mailman.testing.helpers import (
+    event_subscribers, get_queue_messages,
+    specialized_message_from_string as mfs)
+from mailman.testing.layers import ConfigLayer
+
+
+class TestDMARC(unittest.TestCase):
+    layer = ConfigLayer
+    maxDiff = None
+
+    def setUp(self):
+        self._mlist = create_list('ant@example.com')
+        self._msg = mfs("""\
+From: anne@example.com
+To: test@example.com
+Subject: Ignore
+
+""")
+
+    def test_discard(self):
+        msgdata = dict(dmarc_action='discard')
+        # When a message is discarded, the only artifacts are a log message
+        # and an event.  Catch the event to prove it happened.
+        events = []
+        def handler(event):                         # noqa: E306
+            if isinstance(event, DiscardEvent):
+                events.append(event)
+        with event_subscribers(handler):
+            process_chain(self._mlist, self._msg, msgdata, start_chain='dmarc')
+        self.assertEqual(len(events), 1)
+        self.assertIs(events[0].msg, self._msg)
+
+    def test_reject(self):
+        msgdata = dict(
+            dmarc_action='reject',
+            moderation_reasons=['DMARC violation'],
+            )
+        # When a message is reject, an event will be triggered and the message
+        # will be bounced.
+        events = []
+        def handler(event):                         # noqa: E306
+            if isinstance(event, RejectEvent):
+                events.append(event)
+        with event_subscribers(handler):
+            process_chain(self._mlist, self._msg, msgdata, start_chain='dmarc')
+        self.assertEqual(len(events), 1)
+        self.assertIs(events[0].msg, self._msg)
+        items = get_queue_messages('virgin', expected_count=1)
+        # Unpack the rejection message.
+        rejection = items[0].msg.get_payload(0).get_payload()
+        self.assertEqual(rejection, """\
+Your message to the Ant mailing-list was rejected for the following
+reasons:
+
+DMARC violation
+
+The original message as received by Mailman is attached.
+""")
diff --git a/src/mailman/commands/cli_withlist.py b/src/mailman/commands/cli_withlist.py
index b93d9b153..d2b706e34 100644
--- a/src/mailman/commands/cli_withlist.py
+++ b/src/mailman/commands/cli_withlist.py
@@ -80,7 +80,7 @@ def start_python(overrides, banner):
     # Set the tab completion.
     with ExitStack() as resources:
         try:                                    # pragma: nocover
-            import readline, rlcompleter        # noqa: F401, E401
+            import readline, rlcompleter        # noqa: F401,E401
         except ImportError:                     # pragma: nocover
             print(_('readline not available'), file=sys.stderr)
             pass
diff --git a/src/mailman/core/i18n.py b/src/mailman/core/i18n.py
index 69abe3b9d..d5aa06b5c 100644
--- a/src/mailman/core/i18n.py
+++ b/src/mailman/core/i18n.py
@@ -47,3 +47,21 @@ def initialize(application=None):
 def handle_ConfigurationUpdatedEvent(event):
     if isinstance(event, ConfigurationUpdatedEvent):
         _.default = event.config.mailman.default_language
+
+
+@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
diff --git a/src/mailman/core/pipelines.py b/src/mailman/core/pipelines.py
index df07bc608..4265d24d1 100644
--- a/src/mailman/core/pipelines.py
+++ b/src/mailman/core/pipelines.py
@@ -55,7 +55,7 @@ def process(mlist, msg, msgdata, pipeline_name='built-in'):
         except RejectMessage as error:
             vlog.info(
                 '{} rejected by "{}" pipeline handler "{}": {}'.format(
-                    message_id, pipeline_name, handler.name, error.message))
+                    message_id, pipeline_name, handler.name, str(error)))
             bounce_message(mlist, msg, error)
 
 
diff --git a/src/mailman/core/tests/test_pipelines.py b/src/mailman/core/tests/test_pipelines.py
index 4ec55798f..3d4ae0ad2 100644
--- a/src/mailman/core/tests/test_pipelines.py
+++ b/src/mailman/core/tests/test_pipelines.py
@@ -48,8 +48,11 @@ class DiscardingHandler:
 class RejectHandler:
     name = 'rejecting'
 
+    def __init__(self, message):
+        self.message = message
+
     def process(self, mlist, msg, msgdata):
-        raise RejectMessage('by test handler')
+        raise RejectMessage(self.message)
 
 
 @implementer(IPipeline)
@@ -66,8 +69,11 @@ class RejectingPipeline:
     name = 'test-rejecting'
     description = 'Rejectinging test pipeline'
 
+    def __init__(self):
+        self.message = 'by test handler'
+
     def __iter__(self):
-        yield RejectHandler()
+        yield RejectHandler(self.message)
 
 
 class TestPostingPipeline(unittest.TestCase):
@@ -109,18 +115,49 @@ testing
             '"discarding": by test handler'))
 
     def test_rejecting_pipeline(self):
-        # If a handler in the pipeline raises DiscardMessage, the message will
-        # be thrown away, but with a log message.
+        # If a handler in the pipeline raises RejectMessage, the post will
+        # be bounced with a log message.
         mark = LogFileMark('mailman.vette')
         process(self._mlist, self._msg, {}, 'test-rejecting')
         line = mark.readline()[:-1]
-        self.assertTrue(line.endswith(
+        self.assertEqual(
+            line[-80:],
+            '<ant> rejected by "test-rejecting" pipeline handler '
+            '"rejecting": by test handler',
+            line)
+        # In the rejection case, the original message will also be in the
+        # virgin queue.
+        items = get_queue_messages('virgin', expected_count=1)
+        self.assertEqual(
+            str(items[0].msg.get_payload(1).get_payload(0)['subject']),
+            'a test')
+        # The first payload contains the rejection reason.
+        payload = items[0].msg.get_payload(0).get_payload()
+        self.assertEqual(payload, 'by test handler')
+
+    def test_rejecting_pipeline_without_message(self):
+        # Similar to above, but without a rejection message.
+        pipeline = config.pipelines['test-rejecting']
+        message = pipeline.message
+        self.addCleanup(setattr, pipeline, 'message', message)
+        pipeline.message = None
+        mark = LogFileMark('mailman.vette')
+        process(self._mlist, self._msg, {}, 'test-rejecting')
+        line = mark.readline()[:-1]
+        self.assertEqual(
+            line[-91:],
             '<ant> rejected by "test-rejecting" pipeline handler '
-            '"rejecting": by test handler'))
+            '"rejecting": [No details are available]',
+            line)
         # In the rejection case, the original message will also be in the
         # virgin queue.
         items = get_queue_messages('virgin', expected_count=1)
-        self.assertEqual(str(items[0].msg['subject']), 'a test')
+        self.assertEqual(
+            str(items[0].msg.get_payload(1).get_payload(0)['subject']),
+            'a test')
+        # The first payload contains the rejection reason.
+        payload = items[0].msg.get_payload(0).get_payload()
+        self.assertEqual(payload, '[No details are available]')
 
     def test_decorate_bulk(self):
         # Ensure that bulk postings get decorated with the footer.
diff --git a/src/mailman/docs/NEWS.rst b/src/mailman/docs/NEWS.rst
index 420e0fbe2..4000c135b 100644
--- a/src/mailman/docs/NEWS.rst
+++ b/src/mailman/docs/NEWS.rst
@@ -23,6 +23,7 @@ Bugs
   discarded.  (Closes #369)
 * Various message holds and rejects that gave 'N/A' as a reason now give an
   appropriate reason.  (Closes #368)
+* Bounce messages are now composed for proper translations.
 
 Command line
 ------------
@@ -39,6 +40,8 @@ Interfaces
   both ``List-ID``s and fully qualified list names, since that's the most
   common use case.  There's now a separate ``.get_by_fqdn()`` which only
   accepts the latter and mirrors the already existing ``.get_by_list_id()``.
+* A new template ``list:user:notice:rejected`` has been added for customizing
+  the bounce message rejection notice.
 
 Other
 -----
diff --git a/src/mailman/interfaces/pipeline.py b/src/mailman/interfaces/pipeline.py
index fac89c442..faccc52d2 100644
--- a/src/mailman/interfaces/pipeline.py
+++ b/src/mailman/interfaces/pipeline.py
@@ -17,13 +17,12 @@
 
 """Interface for describing pipelines."""
 
+from mailman.core.i18n import _, format_reasons
 from public import public
 from zope.interface import Attribute, Interface
 
 
-# For i18n extraction.
-def _(s):
-    return s
+NL = '\n'
 
 
 # These are thrown but they aren't exceptions so don't inherit from
@@ -44,11 +43,20 @@ class DiscardMessage(BaseException):
 class RejectMessage(BaseException):
     """The message will be bounced back to the sender"""
 
-    def __init__(self, message=None):
+    def __init__(self, message=None, reasons=None, substitutions=None):
         self.message = message
+        self.reasons = reasons
+        self.substitutions = ({} if substitutions is None else substitutions)
 
     def __str__(self):
-        return self.message
+        if self.message is None:
+            return _('[No details are available]')
+        reasons = (_('[No reasons given]')
+                   if self.reasons is None
+                   else NL.join(format_reasons(self.reasons)))
+        substitutions = self.substitutions.copy()
+        substitutions['reasons'] = reasons
+        return _(self.message, substitutions)
 
 
 @public
diff --git a/src/mailman/interfaces/template.py b/src/mailman/interfaces/template.py
index 388e95942..ee2466f86 100644
--- a/src/mailman/interfaces/template.py
+++ b/src/mailman/interfaces/template.py
@@ -179,6 +179,7 @@ ALL_TEMPLATES = {
         'list:user:notice:post',
         'list:user:notice:probe',
         'list:user:notice:refuse',
+        'list:user:notice:rejected',
         'list:user:notice:welcome',
         }
     }
diff --git a/src/mailman/mta/deliver.py b/src/mailman/mta/deliver.py
index db069bd36..e614d5bd1 100644
--- a/src/mailman/mta/deliver.py
+++ b/src/mailman/mta/deliver.py
@@ -90,15 +90,15 @@ def deliver(mlist, msg, msgdata):
     if size is None:
         size = len(msg.as_string())
     substitutions = dict(
-        msgid       = msg.get('message-id', 'n/a'),   # noqa: E221, E251
-        listname    = mlist.fqdn_listname,            # noqa: E221, E251
-        sender      = original_sender,                # noqa: E221, E251
-        recip       = len(original_recipients),       # noqa: E221, E251
-        size        = size,                           # noqa: E221, E251
-        time        = t1 - t0,                        # noqa: E221, E251
-        refused     = len(refused),                   # noqa: E221, E251
-        smtpcode    = 'n/a',                          # noqa: E221, E251
-        smtpmsg     = 'n/a',                          # noqa: E221, E251
+        msgid       = msg.get('message-id', 'n/a'),   # noqa: E221,E251
+        listname    = mlist.fqdn_listname,            # noqa: E221,E251
+        sender      = original_sender,                # noqa: E221,E251
+        recip       = len(original_recipients),       # noqa: E221,E251
+        size        = size,                           # noqa: E221,E251
+        time        = t1 - t0,                        # noqa: E221,E251
+        refused     = len(refused),                   # noqa: E221,E251
+        smtpcode    = 'n/a',                          # noqa: E221,E251
+        smtpmsg     = 'n/a',                          # noqa: E221,E251
         )
     template = config.logging.smtp.every
     if template.lower() != 'no':
@@ -141,9 +141,9 @@ def deliver(mlist, msg, msgdata):
         template = config.logging.smtp.failure
         if template.lower() != 'no':
             substitutions.update(
-                recip       = recipient,            # noqa: E221, E251
-                smtpcode    = code,                 # noqa: E221, E251
-                smtpmsg     = smtp_message,         # noqa: E221, E251
+                recip       = recipient,            # noqa: E221,E251
+                smtpcode    = code,                 # noqa: E221,E251
+                smtpmsg     = smtp_message,         # noqa: E221,E251
                 )
             log.info('%s', expand(template, mlist, substitutions))
     # Return the results
diff --git a/src/mailman/rest/tests/test_domains.py b/src/mailman/rest/tests/test_domains.py
index 3bacf7a72..bd6668a5b 100644
--- a/src/mailman/rest/tests/test_domains.py
+++ b/src/mailman/rest/tests/test_domains.py
@@ -346,6 +346,7 @@ class TestDomainTemplates(unittest.TestCase):
                 'list:user:notice:post': '',
                 'list:user:notice:probe': '',
                 'list:user:notice:refuse': '',
+                'list:user:notice:rejected': '',
                 'list:user:notice:welcome': 'http://example.org/welcome',
                 'password': 'some password',
                 'username': 'anne.person',
diff --git a/src/mailman/rest/tests/test_lists.py b/src/mailman/rest/tests/test_lists.py
index 75a81f3cb..0f3b99393 100644
--- a/src/mailman/rest/tests/test_lists.py
+++ b/src/mailman/rest/tests/test_lists.py
@@ -705,6 +705,7 @@ class TestListTemplates(unittest.TestCase):
                 'list:user:notice:post': '',
                 'list:user:notice:probe': '',
                 'list:user:notice:refuse': '',
+                'list:user:notice:rejected': '',
                 'list:user:notice:welcome': 'http://example.org/welcome',
                 'password': 'some password',
                 'username': 'anne.person',
diff --git a/src/mailman/rest/tests/test_root.py b/src/mailman/rest/tests/test_root.py
index cb16caeeb..45adc6075 100644
--- a/src/mailman/rest/tests/test_root.py
+++ b/src/mailman/rest/tests/test_root.py
@@ -283,6 +283,7 @@ class TestSiteTemplates(unittest.TestCase):
                 'list:user:notice:post': '',
                 'list:user:notice:probe': '',
                 'list:user:notice:refuse': '',
+                'list:user:notice:rejected': '',
                 'list:user:notice:welcome': 'http://example.org/welcome',
                 'password': 'some password',
                 'username': 'anne.person',
diff --git a/src/mailman/rules/dmarc.py b/src/mailman/rules/dmarc.py
index 9f9b11673..2741eb1df 100644
--- a/src/mailman/rules/dmarc.py
+++ b/src/mailman/rules/dmarc.py
@@ -298,15 +298,15 @@ class DMARCMitigation:
         if mlist.dmarc_mitigate_action is DMARCMitigateAction.no_mitigation:
             # Don't bother to check if we're not going to do anything.
             return False
-        dn, addr = parseaddr(msg.get('from'))
-        if maybe_mitigate(mlist, addr):
+        display_name, address = parseaddr(msg.get('from'))
+        if maybe_mitigate(mlist, address):
             # If dmarc_mitigate_action is discard or reject, this rule fires
             # and jumps to the 'moderation' chain to do the actual discard.
             # Otherwise, the rule misses but sets a flag for the dmarc handler
             # to do the appropriate action.
             msgdata['dmarc'] = True
             if mlist.dmarc_mitigate_action is DMARCMitigateAction.discard:
-                msgdata['moderation_action'] = 'discard'
+                msgdata['dmarc_action'] = 'discard'
                 with _.defer_translation():
                     # This will be translated at the point of use.
                     msgdata.setdefault('moderation_reasons', []).append(
@@ -324,9 +324,9 @@ class DMARCMitigation:
                         'contact the mailing list owner at ${listowner}.'))
                 msgdata.setdefault('moderation_reasons', []).append(
                     wrap(reason))
-                msgdata['moderation_action'] = 'reject'
+                msgdata['dmarc_action'] = 'reject'
             else:
                 return False
-            msgdata['moderation_sender'] = addr
+            msgdata['moderation_sender'] = address
             return True
         return False
diff --git a/src/mailman/rules/docs/dmarc-mitigation.rst b/src/mailman/rules/docs/dmarc-mitigation.rst
index bee7b3a55..cf7ceeb74 100644
--- a/src/mailman/rules/docs/dmarc-mitigation.rst
+++ b/src/mailman/rules/docs/dmarc-mitigation.rst
@@ -102,7 +102,7 @@ message.
     True
     >>> dump_msgdata(msgdata)
     dmarc             : True
-    moderation_action : discard
+    dmarc_action      : discard
     moderation_reasons: ['DMARC moderation']
     moderation_sender : aperson@example.biz
 
@@ -121,7 +121,7 @@ We can reject the message with a default reason.
     True
     >>> dump_msgdata(msgdata)
     dmarc             : True
-    moderation_action : reject
+    dmarc_action      : reject
     moderation_reasons: ['You are not allowed to post to this mailing list...
     moderation_sender : aperson@example.biz
 
@@ -140,6 +140,6 @@ And, we can reject with a custom message.
     True
     >>> dump_msgdata(msgdata)
     dmarc             : True
-    moderation_action : reject
+    dmarc_action      : reject
     moderation_reasons: ['A silly reason']
     moderation_sender : aperson@example.biz
diff --git a/src/mailman/rules/docs/moderation.rst b/src/mailman/rules/docs/moderation.rst
index d1cc5fd67..8bdcd2f1a 100644
--- a/src/mailman/rules/docs/moderation.rst
+++ b/src/mailman/rules/docs/moderation.rst
@@ -60,9 +60,9 @@ the eventual moderation chain.
     >>> member_rule.check(mlist, member_msg, msgdata)
     True
     >>> dump_msgdata(msgdata)
-    moderation_action : hold
-    moderation_reasons: ['The message comes from a moderated member']
-    moderation_sender : aperson@example.com
+    member_moderation_action: hold
+    moderation_reasons      : ['The message comes from a moderated member']
+    moderation_sender       : aperson@example.com
 
 
 Nonmembers
@@ -107,9 +107,9 @@ rule matches and the message metadata again carries some useful information.
     >>> nonmember_rule.check(mlist, nonmember_msg, msgdata)
     True
     >>> dump_msgdata(msgdata)
-    moderation_action : hold
-    moderation_reasons: ['The message is not from a list member']
-    moderation_sender : bperson@example.com
+    member_moderation_action: hold
+    moderation_reasons      : ['The message is not from a list member']
+    moderation_sender       : bperson@example.com
 
 Of course, the nonmember action can be set to defer the decision, in which
 case the rule does not match.
@@ -161,9 +161,9 @@ nonmember of the list.  The rule also matches.
     >>> nonmember_rule.check(mlist, msg, msgdata)
     True
     >>> dump_msgdata(msgdata)
-    moderation_action : hold
-    moderation_reasons: ['The message is not from a list member']
-    moderation_sender : cperson@example.com
+    member_moderation_action: hold
+    moderation_reasons      : ['The message is not from a list member']
+    moderation_sender       : cperson@example.com
 
     >>> dump_list(mlist.members.members, key=memberkey)
     <Member: Anne Person <aperson@example.com>
diff --git a/src/mailman/rules/moderation.py b/src/mailman/rules/moderation.py
index 7f78d3ce7..26f04d632 100644
--- a/src/mailman/rules/moderation.py
+++ b/src/mailman/rules/moderation.py
@@ -82,7 +82,7 @@ class MemberModeration:
         elif action is not None:
             # We must stringify the moderation action so that it can be
             # stored in the pending request table.
-            msgdata['moderation_action'] = action.name
+            msgdata['member_moderation_action'] = action.name
             msgdata['moderation_sender'] = sender
             with _.defer_translation():
                 # This will be translated at the point of use.
@@ -94,7 +94,7 @@ class MemberModeration:
 
 
 def _record_action(msgdata, action, sender, reason):
-    msgdata['moderation_action'] = action
+    msgdata['member_moderation_action'] = action
     msgdata['moderation_sender'] = sender
     msgdata.setdefault('moderation_reasons', []).append(reason)
 
diff --git a/src/mailman/rules/tests/test_moderation.py b/src/mailman/rules/tests/test_moderation.py
index e08bba480..46d848b42 100644
--- a/src/mailman/rules/tests/test_moderation.py
+++ b/src/mailman/rules/tests/test_moderation.py
@@ -142,9 +142,9 @@ A message body.
             msgdata = {}
             result = rule.check(self._mlist, msg, msgdata)
             self.assertTrue(result, 'NonmemberModeration rule should hit')
-            self.assertIn('moderation_action', msgdata)
+            self.assertIn('member_moderation_action', msgdata)
             self.assertEqual(
-                msgdata['moderation_action'], action_name,
+                msgdata['member_moderation_action'], action_name,
                 'Wrong action for {}: {}'.format(address, action_name))
 
     def test_nonmember_fallback_to_list_defaults(self):
@@ -166,7 +166,7 @@ A message body.
         msgdata = {}
         result = rule.check(self._mlist, msg, msgdata)
         self.assertTrue(result)
-        self.assertEqual(msgdata['moderation_action'], 'hold')
+        self.assertEqual(msgdata['member_moderation_action'], 'hold')
         # As a side-effect, Anne has been added as a nonmember with a
         # moderation action that falls back to the list's default.
         anne = self._mlist.nonmembers.get_member('anne@example.com')
@@ -177,7 +177,7 @@ A message body.
         # This time, the message should be discarded.
         result = rule.check(self._mlist, msg, msgdata)
         self.assertTrue(result)
-        self.assertEqual(msgdata.get('moderation_action'), 'discard')
+        self.assertEqual(msgdata.get('member_moderation_action'), 'discard')
 
     def test_member_fallback_to_list_defaults(self):
         # https://gitlab.com/mailman/mailman/issues/189
@@ -201,14 +201,14 @@ A message body.
         msgdata = {}
         result = rule.check(self._mlist, msg, msgdata)
         self.assertTrue(result)
-        self.assertEqual(msgdata.get('moderation_action'), 'accept')
+        self.assertEqual(msgdata.get('member_moderation_action'), 'accept')
         # Then the list's default member action is changed.
         self._mlist.default_member_action = Action.hold
         msg.replace_header('Message-ID', '<bee>')
         # This time, the message is held.
         result = rule.check(self._mlist, msg, msgdata)
         self.assertTrue(result)
-        self.assertEqual(msgdata.get('moderation_action'), 'hold')
+        self.assertEqual(msgdata.get('member_moderation_action'), 'hold')
 
     def test_linked_address_nonmembermoderation_misses(self):
         # Anne subscribes to a mailing list as a user with her preferred
diff --git a/src/mailman/templates/en/list:user:notice:rejected.txt b/src/mailman/templates/en/list:user:notice:rejected.txt
new file mode 100644
index 000000000..b8e5aab53
--- /dev/null
+++ b/src/mailman/templates/en/list:user:notice:rejected.txt
@@ -0,0 +1,6 @@
+Your message to the $listname mailing-list was rejected for the following
+reasons:
+
+$reasons
+
+The original message as received by Mailman is attached.