Several times people told me that message sent to mailman list just disappears and never sent to its subscribers. All messages had attachements, mostly excel files and doc files.

While i was trying to send some file attached into mail list - it was ok. I reset all options that could affect to the safe values:

max_message_size: 0
max_days_to_hold: 5  <- hold before automatic discarding
default_member_moderation: no
member_moderation_action: hold
generic_nonmember_action: hold
forward_auto_discards: yes
require_excplicite_destination: no
max_num_recipients: 10

And after all this i got discarded message again:

Sep 04 23:33:45 2006 (99752) Message discarded, msgid:
 <01f701c6d061$67f01430$0dcc090a@foo.bar>

I found only one place where this even occurs - it's in Mailman/Queue/IncomingRunner.py, Class IncomingRunner, method _dopipeline. Here's the code fragment:

line sys.modules[modname].process(mlist, msg, msgdata) calls method process() of one of those handlers, located in Mailman/Handlers. I grep'ed that dir and found that only followin handlers raise Errors.DiscardMessage exception:

• MimeDel.py
• Moderate.py
• Scrubber.py
• SpamDetect.py
• ToDigest.py

In my case mlist.filter_action == 3 though. Anyway, I was wondered when i found mlist.filter_content set to 1. Though filter_mime_types was empty and xls/doc wasn't in filter_filename_extensions

Im not sure if i found the real reason of why message was discrded, but i set filter_action to 0. In this case, the handler won't process the message at all:

And just to make sure i will know the name of the handler which discard the message next time ( if this happens again), i added a bit more info to the logging string in _dopipeline method: