[Mailman-Users] Message discarded without reason logged in vette

[Mark Sapiro]

On 7/7/16 3:58 PM, Hirayama, Pat wrote:
> So, I found a 10 year old post where Mark Sapiro described some of the reasons why "Message discarded" with only a message id and no reason happens:
> 
> Examples are when nothing is left after content filtering, a post from
> a moderated user when action is discard, a post from a non-member in
> discard_these_nonmembers, a post from a non-member with generic action
> discard, some cases of a text/html post when ARCHIVE_HTML_SANITIZER =
> 0 and a post matching a header_filter_rule with discard action.
> 
> I was wondering if there was a more complete list someplace?  Mostly because I had this happen to one of my users 3 weeks ago, and I think that I've managed to rule out everything that Mark wrote back then.


If the message in the vette log is "Message discarded, msgid: <...>",
that message is only produced in standard Mailman by IncomingRunner when
a handler raises DiscardMessage. Again in standard Mailman, the only
Handlers that do that are:

MimeDel
 - content filtering removes the entire message and filter_action is
other than Reject

Moderate
 - a post is from a moderated member with member_moderation_action Discard
 - a post is from a non-member in discard_these_nonmembers or with
generic_nonmember_action Discard

Scrubber
 - if the top level MIME type is text/html and ARCHIVE_HTML_SANITIZER =
0 (not the default, and this only applies if scrub_nondigest is Yes)

SpamDetect
 - when a message matches KNOWN_SPAMMERS
 - A post is From: a domain with DMARC p=reject (or maybe quarantine)
and dmarc_moderation_action is Discard
 - a message matches header_filter_rules with Discard action or with
Reject action and the message is to -owner

This is the current complete list for standard GNU Mailman. It is
essentially the same as in the old post with the addition of
dmarc_moderation_action. If your Mailman is from a downstream package or
has local mods, you can

grep -r DiscardMessage /path/to/Mailman/Handlers

to see if there are others

-- 
Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan