[Mailman-Users] Bounce Processing -- Disable/Removal Notification

Mark Sapiro msapiro at value.net
Sun Sep 30 07:13:05 CEST 2007

Greg Sims wrote:
>I believe you have the problem narrowed down. Here are the answers to your
>Do these entries say "sending listname list probe to: user at example.com
>(score 5.0 >= 5.0)"?
>>> Yes
>Is VERP_PROBES = Yes in mm_cfg.py (or is this Mailman 2.1.5 where VERP
>probes was unconditionally on)?
>>> 2.1.5
>If so, do you see in the bounce log that a probe was sent but didn't
>bounce? If so, it is likely that your MTA doesn't recognize the '+'
>delimiter to separate the VERP probe token from the local part of an
>address and can't deliver the bounce.
>>> I believe so.  A score of 5.0 is reached, the probe message is sent
>>> and the next thing I see is another bounce with a score of 1.0.

OK. The probes aren't bouncing or the bounced probes aren't delivered
back to Mailman. It's extremely unlikely that no probes are bouncing,
so the most likely thing is the probe bounces aren't getting back to


>>> The server is using Qmail.  What can I do to fix this problem or work
>>> around it.  Do I need to remove entries from the subscription manually?
>>> If this is the case, this will need to be automated in some way as it
>>> will be very time consuming.

There a couple of possibilities. First, I suggest that you verify that
mail to user+xyz at example.com is not properly delivered to user where
example.com is your mail domain and user is a valid local address.
Then we know for sure that this is the problem. Or, you could check
qmail's logs from the time a probe bounce was sent to see the return
in the log and what happened to it.

If possible, you could upgrade to a later than 2.1.5 Mailman version in
which you can set VERP_PROBES = No in mm_cfg.py to avoid the issue.

There is some information on qmail at
<http://www.list.org/mailman-install/qmail-issues.html>. It looks like
in order to make this recognition work with qmail, you may have to put

VERP_PROBE_FORMAT = '%(bounces)s-+%(token)s'
VERP_PROBE_REGEXP = r'^(?P<bounces>.*?)-\+(?P<token>[^@]+)@.*$'

mm_cfg.py (the install manual talks about VERP_FORMAT and VERP_REGEXP,
but that is not what we need here). This changes the delimiter from
'+' to '-+' and changes the recognizer to recognize it. It looks like
you also need and additional .qmail-$i-bounces-default alias file ($i
is the list name) for each affected list.

There may be a way to change qmail's VERP delimiter from '-' to '+'
which may be enough by itself, but I don't know.

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

More information about the Mailman-Users mailing list