src/mailman/mta/verp.py

   1 # Copyright (C) 2009-2016 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 import logging
  21
  22 from mailman import public
  23 from mailman.config import config
  24 from mailman.mta.base import IndividualDelivery
  25 from mailman.utilities.email import split_email
  26 from mailman.utilities.string import expand
  27
  28
  29 DOT = '.'
  30 log = logging.getLogger('mailman.smtp')
  31
  32
  33 @public
  34 class VERPMixin:
  35     """Mixin for VERP functionality.
  36
  37     This works by overriding the base class's _get_sender() method to return
  38     the VERP'd envelope sender.  It expects the individual recipient's address
  39     to be squirreled away in the message metadata.
  40     """
  41     def _get_sender(self, mlist, msg, msgdata):
  42         """Return the recipient's address VERP encoded in the sender.
  43
  44         :param mlist: The mailing list being delivered to.
  45         :type mlist: `IMailingList`
  46         :param msg: The original message being delivered.
  47         :type msg: `Message`
  48         :param msgdata: Additional message metadata for this delivery.
  49         :type msgdata: dictionary
  50         """
  51         sender = super()._get_sender(mlist, msg, msgdata)
  52         if msgdata.get('verp', False):
  53             log.debug('VERPing %s', msg.get('message-id'))
  54             recipient = msgdata['recipient']
  55             sender_mailbox, sender_domain = split_email(sender)
  56             # Encode the recipient's address for VERP.
  57             recipient_mailbox, recipient_domain = split_email(recipient)
  58             if recipient_domain is None:
  59                 # The recipient address is not fully-qualified.  We can't
  60                 # deliver it to this person, nor can we craft a valid verp
  61                 # header.  I don't think there's much we can do except ignore
  62                 # this recipient.
  63                 log.info('Skipping VERP delivery to unqual recip: %s',
  64                          recipient)
  65                 return sender
  66             return '{0}@{1}'.format(
  67                 expand(config.mta.verp_format, dict(
  68                     bounces=sender_mailbox,
  69                     local=recipient_mailbox,
  70                     domain=DOT.join(recipient_domain))),
  71                 DOT.join(sender_domain))
  72         else:
  73             return sender
  74
  75     def avoid_duplicates(self, mlist, msg, msgdata):
  76         """Flag the message for duplicate avoidance.
  77
  78         We can flag the mail as a duplicate for each member, if they've
  79         already received this message, as calculated by Message-ID.  See
  80         `AvoidDuplicates.py`_ for details.
  81         """
  82         recipient = msgdata['recipient']
  83         del msg['x-mailman-copy']
  84         if recipient in msgdata.get('add-dup-header', {}):
  85             msg['X-Mailman-Copy'] = 'yes'
  86
  87
  88 @public
  89 class VERPDelivery(VERPMixin, IndividualDelivery):
  90     """Deliver a unique message to the MSA for each recipient."""
  91
  92     def __init__(self):
  93         """See `IndividualDelivery`."""
  94         super().__init__()
  95         self.callbacks.append(self.avoid_duplicates)