# Copyright (C) 1998,1999,2000,2001,2002 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
"""Parse RFC 1894 (i.e. DSN) bounce formats."""
from email.Iterators import typed_subpart_iterator
from email.Utils import parseaddr
from cStringIO import StringIO
def check(msg):
# Iterate over each message/delivery-status subpart
addrs = []
for part in typed_subpart_iterator(msg, 'message', 'delivery-status'):
if not part.is_multipart():
# Huh?
continue
# Each message/delivery-status contains a list of Message objects
# which are the header blocks. Iterate over those too.
for msgblock in part.get_payload():
# We try to dig out the Original-Recipient (which is optional) and
# Final-Recipient (which is mandatory, but may not exactly match
# an address on our list). Some MTA's also use X-Actual-Recipient
# as a synonym for Original-Recipient, but some apparently use
# that for other purposes :(
#
# Also grok out Action so we can do something with that too.
action = msgblock.get('action', '')
# BAW: Should we treat delayed bounces the same? Yes, because if
# the transient problem clears up, they should get unbounced. The
# other problem is what to do about a DSN that has both delayed
# and failed actions in multiple header blocks? We're not
# architected to handle that. ;/
if action.lower() not in ('failed', 'failure', 'delayed'):
# Some non-permanent failure, so ignore this block
continue
params = []
foundp = 0
for header in ('original-recipient', 'final-recipient'):
for k, v in msgblock.get_params([], header):
if k.lower() == 'rfc822':
foundp = 1
else:
params.append(k)
if foundp:
# Note that params should already be unquoted.
addrs.extend(params)
break
# Uniquify
rtnaddrs = {}
for a in addrs:
if a is not None:
realname, a = parseaddr(a)
rtnaddrs[a] = 1
return rtnaddrs.keys()
def process(msg):
# The report-type parameter should be "delivery-status", but it seems that
# some DSN generating MTAs don't include this on the Content-Type: header,
# so let's relax the test a bit.
if not msg.is_multipart() or msg.get_subtype() <> 'report':
return None
return check(msg)
