[Mailman-Users] Automatic bounce processing; listname-bounces vs. listname-bounces+XXXX

Mark Sapiro mark at msapiro.net
Fri Jan 2 17:36:33 CET 2009

John Wesley Simpson Hibbs wrote:

>Our mailing lists had been processing bounces correctly for quite some
>For some reason though, this has stopped functioning properly.

Did you just upgrade to Mailman 2.1.11?

>Bounces were coming back to list-bounces+XXXX, and are now coming back
>to list-bounces, without the XXXX.

The difference is Mailman's VERP

>The setting "Should Mailman perform automatic bounce processing?" is set
>to yes.
>Any help or advice would be greatly appreciated.
>What I am getting now:

[Bounce of a Password reminder snipped.]

Is it only password reminders that you are seeing as unrecognized

There are two things going on now. The password reminder wasn't VERP'd
because this is controlled by VERP_PASSWORD_REMINDERS which is a
separate setting in mm_cfg.py from those that control VERPing of list

In 2.1.11, the VERPing of the password reminder wouldn't matter because
of two things:

1) Password reminders don't come from a regular list. Since reminders
may be for more that one list when the address is subscribed to more
than one list, the reminder is sent from the site list (this is not
new in 2.1.11).

2) Site list bounces are handled differently in 2.1.11. In the past, if
something from the site list bounced, at least in some cases it was
handled as an ordinary bounce of a message from the site list. In most
cases, these bounces were bounces of password reminders, and the
remindee is not a member of the site list anyway, so the bounce, if
recognized, would be ignored. The 2.1.11 change is to forward all site
list bounces to the site list owner without even trying to recognize

However, upon looking closer, I see that this probably isn't what's
going on here, because the forward to the site list owner as above is
not wrapped in an "unrecognized bounce" message.

I tried running that message through the current recognizers, and it is
recognized, so now it looks to me as if:

1) you have an older Mailman that doesn't recognize that particular
bounce, and

2) You have not set "VERP_PASSWORD_REMINDERS = Yes" in mm_cfg.py.

Actually, It is a good thing you saw this unrecognized bounce. Had it
been recognized, it would have been ignored as the user probably isn't
a member of the site list.

What happens in these cases is a list member sets delivery off for some
reason and then forgets about the list. Then the address dies and the
only mail to the address is the monthly password reminder which even
if it bounces and is recognized, never removes the dead address from
the list of which it is a member.

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

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