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

Mark Sapiro msapiro at value.net
Mon Jun 5 16:49:46 CEST 2006

David Lee wrote:
>   Fedora Core 5
>   Mailman 2.1.8 (RPM: mailman-2.1.8-0.FC5.1)
>   sendmail 8.13.6 (RPM: sendmail-8.13.6-0.FC5.1)
>On the test list for our staff (89 members), some of the emails are
>failing, while others succeed.  On a failure email:
>1. it only reaches 59 (out of 89) recipients;

What is in Mailman's 'smtp', 'smtp-failure' and 'bounce' logs?
Specifically, are there any bounces recorded in the bounce log, (Is
bounce processing turned on for the list?) and how many recipients are
indicated in the smtp log entry?

>2. it loses the hidden headers ("Received:" etc.) prior to the Mailman
>   expansion;

Mailman doesn't remove any Received: headers.

>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).

Are these the actual headers in the raw message or just what an MUA
shows? If the latter, see
If the former, I suspect Exchange.

>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.)

>5. The mailman log files (bounce,post,smtp,vette) don't show anything
>   unusual at all.

See item 1 above - what is the number of recipiients in the smtp log

>6. In the body of one of the emails I noticed that what the user had
>   typed as "===========" (a set of equals signs as a visual underliner)
>   appeared as "=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D...", as though
>   some MIME misunderstanding had occured.

That is a raw rendering of a quoted-printable encoding. If you are
looking at a raw mesage and it has a "Content-Transfer-Encoding:
quoted-printable" header, this is normal. Otherwise, the encoding is
getting lost somewhere. It's possible, but unlikely that Mailman did
it. Bugs in this area should be fixed in 2.1.8.

>A thought: The emails are emanating from Exchange 2003, Service Pack 2.
>Might Exchange be generating something non-conformant (its bug) which
>Mailman could then be tripping over (Mailman problem)?

Exchange can screw up anything, but once the message gets to Mailman,
if it is sent at all, it should be sent to all eligible members. Are
all 89 members non-digest and delivery enabled?

Are there or were there ever Topics defined for the list? (I really
want to know the recipient count from the 'smtp' log.)

>Incidentally, one of the mail names on the list contains an apostrophe of
>the form: Someone.O'Surname at our.site .  We have seen this sort of thing
>cause trouble very occasionally on other email systems.  But if that
>really were relevant, then I would expect it to be consistent for all the
>mails to the list, not just some of them.

If this is an issue, it would only affect the one user unless sendmail
doesn't like it somehow and drops it and either all preceeding or
following RCPT addresses in that transaction.

I just reread the initial 'fails sometimes' part which I sort of
ignored. This is more puzzling, but most of what I ask above is still
relevant. Could there be some kind of anti-spam content filtering
affecting only the 30 missing? Are the failures from different posters
than the successes? Again, on the failed posts, what is the recipient
count from the 'smtp' log - what does sendmail's maillog say?

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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