[Mailman-Users] VERP active where it shouldn't

Mark Sapiro msapiro at value.net
Fri Jun 2 06:56:06 CEST 2006

schaefer at alphanet.ch wrote:
>I am running a Mailman from Debian stable (2.1.5-8sarge2), and I experimented
>the following issue:
>   - even if disabled in Defaults.py and not enabled in mm_cfg.py,
>     VERP seems to be activated from time to time. I am guessing it is
>     activated only when something already bounced on a user (?).
>     Most mail sent out don't have the VERP (user=host+id) stuff at all
>     as Sender:, and when they have something it's a cookie:
>   gull-annonces-bounces+4ae5d0b7d6547f114afac76d551c9dfbbc3f212e at lists.alphanet.ch

That's a VERP probe.

>My questions:
>   - is there a `mailman_display_config' command which would return the
>     *actually used* mailman configuration (maybe I am looking at the
>     wrong config file or Defaults.py file) ?


>   - how to disable VERP *completely * ?
>In my case, VERP cannot work, because + is *not* used for multi-addresses
>Excerpt from config:
>   grep VERP mm_cfg.py /usr/lib/mailman/Mailman/Defaults.py

mm_cfg.py should be in the same directory as Defaults.py unless this is
a Debian thing.


You seem to have edited out quite a bit of the grep result :-)

You are running Mailman 2.1.5. VERP probes were introduced in 2.1.5 and
couldn't be turned off. This was recognized to be a mistake, so
beginning in 2.1.6 they are controlled by
VERP_PROBES which defaults to No.

In 2.1.5, you could effectively change the sender of the probe from

gull-annonces-bounces+4ae5d0b7d6547f114afac76d551c9dfbbc3f212e at lists.alphanet.ch


gull-annonces-bounces at lists.alphanet.ch

by changing VERP_PROBE_FORMAT, but this will break bounce processing
because in 2.1.5, disabling a bouncing user relies on receiving a
bounced probe with the token.

Your choices are:

Upgrade (maybe not easy/possible with a Debian package).

Complain to Debian.

Modify Mailman/Bouncer.py to either implement mm_cfg.VERP_PROBES or
just remove VERP probes all together. See

Turn off bounce processing for the list.

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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