# Copyright (C) 2002-2008 by the Free Software Foundation, Inc. # # This program 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 2 # of the License, or (at your option) any later version. # # This program 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 this program; if not, write to the Free Software # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. """If the user wishes it, do not send duplicates of the same message. This module keeps an in-memory dictionary of Message-ID: and recipient pairs. If a message with an identical Message-ID: is about to be sent to someone who has already received a copy, we either drop the message, add a duplicate warning header, or pass it through, depending on the user's preferences. """ from email.Utils import getaddresses, formataddr from Mailman import mm_cfg COMMASPACE = ', ' try: True, False except NameError: True = 1 False = 0 def process(mlist, msg, msgdata): recips = msgdata['recips'] # Short circuit if not recips: return # There is an issue with addresses in To: or Cc: that differ in # case from the MemberCPAddresses in recips. We can't just # lower-case everything because we still want CP addresses in # the final recips list, so we lower case the keys. # Seed this set with addresses we don't care about dup avoiding explicit_recips = {} listaddrs = [mlist.GetListEmail(), mlist.GetBouncesEmail(), mlist.GetOwnerEmail(), mlist.GetRequestEmail()] for addr in listaddrs: explicit_recips[addr.lower()] = True # Figure out the set of explicit recipients ccaddrs = {} for header in ('to', 'cc', 'resent-to', 'resent-cc'): addrs = getaddresses(msg.get_all(header, [])) if header == 'cc': for name, addr in addrs: ccaddrs[addr.lower()] = name, addr for name, addr in addrs: if not addr: continue # Ignore the list addresses for purposes of dup avoidance explicit_recips[addr.lower()] = True # Now strip out the list addresses for addr in listaddrs: del explicit_recips[addr.lower()] if not explicit_recips: # No one was explicitly addressed, so we can't do any dup collapsing return newrecips = [] for r in recips: # If this recipient is explicitly addressed... if explicit_recips.has_key(r.lower()): send_duplicate = True # If the member wants to receive duplicates, or if the recipient # is not a member at all, just flag the X-Mailman-Duplicate: yes # header. if mlist.isMember(r) and \ mlist.getMemberOption(r, mm_cfg.DontReceiveDuplicates): send_duplicate = False # We'll send a duplicate unless the user doesn't wish it. If # personalization is enabled, the add-dupe-header flag will add a # X-Mailman-Duplicate: yes header for this user's message. if send_duplicate: msgdata.setdefault('add-dup-header', {})[r] = True newrecips.append(r) elif ccaddrs.has_key(r.lower()): del ccaddrs[r.lower()] else: # Otherwise, this is the first time they've been in the recips # list. Add them to the newrecips list and flag them as having # received this message. newrecips.append(r) # Set the new list of recipients msgdata['recips'] = newrecips # RFC 2822 specifies zero or one CC header del msg['cc'] if ccaddrs: msg['Cc'] = COMMASPACE.join([formataddr(i) for i in ccaddrs.values()])