src/mailman/mta/verp.py

   1 # Copyright (C) 2009 by the Free Software Foundation, Inc.
   2 #
   3 # This file is part of GNU Mailman.
   4 #
   5 # GNU Mailman is free software: you can redistribute it and/or modify it under
   6 # the terms of the GNU General Public License as published by the Free
   7 # Software Foundation, either version 3 of the License, or (at your option)
   8 # any later version.
   9 #
  10 # GNU Mailman is distributed in the hope that it will be useful, but WITHOUT
  11 # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12 # FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13 # more details.
  14 #
  15 # You should have received a copy of the GNU General Public License along with
  16 # GNU Mailman.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 """VERP delivery."""
  19
  20 from __future__ import absolute_import, unicode_literals
  21
  22 __metaclass__ = type
  23 __all__ = [
  24     'VERPDelivery',
  25     'VERPMixin',
  26     ]
  27
  28
  29 import logging
  30
  31 from mailman.config import config
  32 from mailman.email.utils import split_email
  33 from mailman.mta.base import IndividualDelivery
  34 from mailman.utilities.string import expand
  35
  36
  37 DOT = '.'
  38 log = logging.getLogger('mailman.smtp')
  39
  40
  41 \f
  42 class VERPMixin:
  43     """Mixin for VERP functionality.
  44
  45     This works by overriding the base class's _get_sender() method to return
  46     the VERP'd envelope sender.  It expects the individual recipient's address
  47     to be squirreled away in the message metadata.
  48     """
  49     def _get_sender(self, mlist, msg, msgdata):
  50         """Return the recipient's address VERP encoded in the sender.
  51
  52         :param mlist: The mailing list being delivered to.
  53         :type mlist: `IMailingList`
  54         :param msg: The original message being delivered.
  55         :type msg: `Message`
  56         :param msgdata: Additional message metadata for this delivery.
  57         :type msgdata: dictionary
  58         """
  59         sender = super(VERPMixin, self)._get_sender(mlist, msg, msgdata)
  60         if msgdata.get('verp', False):
  61             recipient = msgdata['recipient']
  62             sender_mailbox, sender_domain = split_email(sender)
  63             # Encode the recipient's address for VERP.
  64             recipient_mailbox, recipient_domain = split_email(recipient)
  65             if recipient_domain is None:
  66                 # The recipient address is not fully-qualified.  We can't
  67                 # deliver it to this person, nor can we craft a valid verp
  68                 # header.  I don't think there's much we can do except ignore
  69                 # this recipient.
  70                 log.info('Skipping VERP delivery to unqual recip: %s', recip)
  71                 return sender
  72             return '{0}@{1}'.format(
  73                 expand(config.mta.verp_format, dict(
  74                     bounces=sender_mailbox,
  75                     local=recipient_mailbox,
  76                     domain=DOT.join(recipient_domain))),
  77                 DOT.join(sender_domain))
  78         else:
  79             return sender
  80
  81     def avoid_duplicates(self, mlist, msg, msgdata):
  82         """Flag the message for duplicate avoidance.
  83
  84         We can flag the mail as a duplicate for each member, if they've
  85         already received this message, as calculated by Message-ID.  See
  86         `AvoidDuplicates.py`_ for details.
  87         """
  88         recipient = msgdata['recipient']
  89         del msg['x-mailman-copy']
  90         if recipient in msgdata.get('add-dup-header', {}):
  91             msg['X-Mailman-Copy'] = 'yes'
  92
  93
  94 \f
  95 class VERPDelivery(VERPMixin, IndividualDelivery):
  96     """Deliver a unique message to the MSA for each recipient."""
  97
  98     def __init__(self):
  99         """See `IndividualDelivery`."""
 100         super(VERPDelivery, self).__init__()
 101         self.callbacks.append(self.avoid_duplicates)