[Mailman-Users] partial (silent) non-delivery

Mark Sapiro msapiro at value.net
Mon Jun 5 18:34:11 CEST 2006

David Lee wrote:

>smtp:  All cases:
>     <...> smtp to ourlist for 89 recips, completed in ...
>smtp-failure:  Nothing
>bounce:  No error indications.
>"bounce processing" webpage indicates "Yes" for all the yes/no tickboxes.

OK. This tells us that Mailman delivered the post to sendmail for 89
recipients and there were no errors reported back to Mailman at the
SMTP transaction level and no subsequent bounces (recognized bounces
would be counted in the bounce log and unrecognized bounces forwarded
to the list owner.

>> >2. it loses the hidden headers ("Received:" etc.) prior to the Mailman
>> >   expansion;
>> Mailman doesn't remove any Received: headers.
>On these duff emails, the headers prior to Mailman are absent.  Something
>has removed them.  I'm speculating (and it is mere speculation without
>evidence!) that a badly formatted incoming (or mismatched content;
>8-bit-isms, etc.) email might be exposing some sort of lurking problem in

If there were such a lurking problem, I can't see how it would cause
this problem. The message gets all the way through Mailman to the
'out' queue and has 89 recipients. The problem would have to cause
SMTPDirect to drop some recipients yet still count them. It's hard to
see how this could happen.

Is there anything in Mailman's error log? Anything in the 'shunt' queue
(qfiles/shunt directory)?

>> >3. Instead of:
>> >      From: a.n.other at our.site
>> >      Sender: ourlist-bounces at our.site
>> >   we see just:
>> >      From: ourlist-bounces at our.site
>> >   (no sender; "From" replaced by expected "Sender" contents).

Always, or just on problem cases? Assuming SMTPDirect is unmodified, it
always adds a "Sender: ourlist-bounces at our.site" header to the
outgoing message. Thus, deletion of Sender: must be happening after

>> >4. The sendmail log shows one of the names to get truncated (from
>> >   "a.b.longname at our.site" to "a.b.lon at our.site".
>> If the member address on the list is "a.b.longname at our.site", mailman
>> won't change it. (Unless maybe it's the one with the apostrophe, but
>> even then, I'd look outside Mailman first.)
>Again, this was just an observation.  Something, somewhere is going wrong,
>and this is a _set_ of symptoms on such emails.

So this only occurs on the problem mails? wierd!

>> Are there or were there ever Topics defined for the list? (I really
>> want to know the recipient count from the 'smtp' log.)
>"Topics"?  I'm new to Mailman (but with several years email experience).
>Guide me!

Don't worry about Topics. This would only be relevant if the recipient
count in the 'smtp' log were 59 in the problem cases.

>Shall I zip up the logs and email them to you off-list?  (I've had a good
>look through them, but you may still spot something I've missed.)

Not yet.

>Are there any debug/log/trace things/flags/switches that I could enable?

There are no extra debugging switches to get more log output.

You could do the following:

Edit the file Mailman/Handlers/SMTPDirect.py

The last line in the file is:


Following this, add

    syslog('smtp', 'Msgid: %s, Chunk sent to: %s', msgid, recips)

Indent this the same amount (4 spaces) as the line above. This will log
the list of recipients for each (possibly only one depending on other
settings) SMTP transaction. After editing the file, you need to do
'bin/mailmanctl restart' to load the changed module.

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

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