1 files changed, 74 insertions, 8 deletions

diff --git a/cron/qrunner b/cron/qrunner
index b4e6ac43f..23fb41df1 100644
--- a/cron/qrunner
+++ b/cron/qrunner
@@ -6,19 +6,72 @@
 # 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 
+# along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 
-"""Attempt redelivery for all messages that had delivery problems.
+"""Deliver queued messages.
 """
 
+# A typical Mailman list exposes four aliases which point to three different
+# wrapped scripts.  E.g. for a list named `mylist', you'd have:
+#
+# mylist         -> post
+# mylist-admin   -> mailowner
+# mylist-request -> mailcmd
+# mylist-owner   -> mailowner (through an alias to mylist-admin)
+#
+# Only 3 scripts are used for historical purposes, and this is unlikely to
+# change to due backwards compatibility.  That's immaterial though since the
+# mailowner script can determine which alias it received the message on.
+#
+# mylist-request is a robot address; it's sole purpose is to process emailed
+# commands in a Majordomo-like fashion.  mylist-admin is supposed to reach the
+# list owners, but it performs one vital step before list owner delivery - it
+# examines the message for bounce content.  mylist-owner is the fallback for
+# delivery to the list owners; it performs no bounce detection, but it /does/
+# look for bounce loops, which can occur if a list owner address is bouncing.
+#
+# So delivery flow of messages look like this:
+#
+# joerandom ---> mylist ---> list members
+#    |                           |
+#    |                           |[bounces]
+#    +-------> mylist-admin <----+ <-------------------------------+
+#    |              |                                              |
+#    |              +--->[internal bounce processing]              |
+#    |                               |                             |
+#    |                               |    [bounce found]           |
+#    |                               +--->[register and discard]   |
+#    |                               |                             |
+#    |                               |     [no bounce found]       |
+#    |                               +---> list owners <------+    |
+#    |                                          |             |    |
+#    |                                          |[bounces]    |    |
+#    +-------> mylist-owner <-------------------+             |    |
+#    |              |                                         |    |
+#    |              |     [bounce loop detected]              |    |
+#    |              +---> [log and discard]                   |    |
+#    |              |                                         |    |
+#    |              +-----------------------------------------+    |
+#    |               [no bounce loop detected]                     |
+#    |                                                             |
+#    |                                                             |
+#    +-------> mylist-request                                      |
+#                   |                                              |
+#                   +---> [command processor]                      |
+#                                 |                                |
+#                                 +---> joerandom                  |
+#                                           |                      |
+#                                           |[bounces]             |
+#                                           +----------------------+
+
 import sys
 import os
 import string
@@ -67,6 +120,17 @@ def dispose_message(mlist, msg, msgdata):
         if mlist.bounce_processing:
             if BouncerAPI.ScanMessages(mlist, mimemsg):
                 return 0
+        # Either bounce processing isn't turned on or the bounce detector
+        # found no recognized bounce format in the message.  In either case,
+        # forward the dang thing off to the list owners.  Be sure to munge the
+        # headers so that any bounces from the list owners goes to the -owner
+        # address instead of the -admin address.  This will avoid bounce
+        # loops.
+        msgdata.update({'recips'  : mlist.owner[:],
+                        'errorsto': mlist.GetOwnerEmail(),
+                        })
+        return HandlerAPI.DeliverToUser(mlist, msg, msgdata)
+    elif msgdata.get('toowner', 0):
         # The message could have been a bounce from a broken list admin
         # address.  About the only other test we can do is to see if the
         # message is appearing to come from a well-known MTA generated
@@ -80,10 +144,12 @@ def dispose_message(mlist, msg, msgdata):
         if senderlhs in mm_cfg.LIKELY_BOUNCE_SENDERS:
             syslog('error', 'bounce loop detected from: %s' % sender)
             return 0
-        # Either bounce processing isn't turned on or the bounce detector
-        # found no recognized bounce format in the message.  In either case,
-        # forward the dang thing off to the list owner.
-        msgdata['recips'] = mlist.owner[:]
+        # Any messages to the owner address must have Errors-To: set back to
+        # the owners address so bounce loops can be broken, as per the code
+        # above.
+        msgdata.update({'recips': mlist.owner[:],
+                        'errorsto': mlist.GetOwnerEmail(),
+                        })
         return HandlerAPI.DeliverToUser(mlist, msg, msgdata)
     elif msgdata.get('torequest', 0):
         mlist.ParseMailCommands(msg)