[Mailman-Users] Many users unsubscribed at once (not by me)

Laura Creighton lac at openend.se
Sun Dec 13 12:01:28 EST 2015

In a message of Sun, 13 Dec 2015 17:11:03 +0100, Hal writes:
>On 13/12/2015 15:53, Laura Creighton wrote:
>> What is more likely is that a member of your list,
>> posts something to the list.  Then mailman tries to deliver the mail
>> to all the subscribers.  When it calls up some_site asking to deliver
>> mail to subscribers who have subscribed from accounts on some_site,
>> some_site says something to the effect of:
>> Drop dead.  We are protecting our users from receiving mail from
>> you!  No matter how many times you ask us to send mail to them,
>> we _won't_ because _we don't like you and your crappy mailing list_.
>So "some_site" in your example are all the mail servers around the world 
>which REFUSE to receive the posting(s) from my mailing list, and thus 
>sends an error message back to my list server's Mailman software.

It could be that you are in such a sad state that many places won't
deal with you, but usually the problem is one site, where you have
many users, and that site won't deal with you.   If your 18 bounces
are all from different places, well, maybe you do have 18 users 
who have all managed to use up their disk quota at the same time.
Especially if people on your list have started sending really, really
large files for some reason.

But if the 18 users are all from the same domain, that is reason to
strongly suspect that the reason mail to these users is bouncing is
that their site isn't talking to you, rather than their disk quota 
is full, they all cancelled their accounts and don't exit, they died,
they got fired and their accounts were removed or any of these
other, legitimate reasons for mail to bounce, which has to do with
a problem with their account.  Their accounts are fine.  You just
cannot send mail to them.

>And as these error messages on my list-server start piling up from 
>various mail servers around the world (i.e. "some_site") Mailman says 
>"OK, enough! The LIST-MEMBER sending those messages has to be banned as 
>messages from him won't receive a vast majority of the other list 
>members anyway, so I'll remove him so it won't happen again".
>Have I more or less understood it correctly?

No.  Let us say you have 5 users on your list, user1 at aol.com, user2 at aol.com,
user3 at aol.com user4 at aol.com and user5 at aol.com.

user1 at aol.com posts a piece of mail to your list.
mailman tries to deliver to user2, user3, user4 and user5 @ aol.com
aol says "drop dead, we don't talk to you because of our DMARC policy"
mail to user2 user3 user4 and user5 bounces.  Their bounce count is 

user2 at aol.com posts a piece of mail to your list.
mailman tries to deliver to user1, user3, user4 and user5 @ aol.com
aol says "drop dead, we don't talk to you because of our DMARC policy"
mail to user1 user3 user4 and user5 bounces.  Their bounce count is 

and so on.  Every time somebody from aol sends mail to the list,
it bounces for every other aol member on your list.  Their bounce
counts increase.  

One day, some message sends some of the bounce counts over the limit
mailman has, after which it says -- Too many bounces!  I cannot
deliver mail to this account!  Unsubscribe this person!  And,
because of the way things have happened you get a triggering message
which causes a lot of unsubscribes _from the same site_.

This is what we think has happened to you.  We would be very pleased
to be mistaken about this, but you have to check the logs to find out
why the mail is bouncing.

Whether 18 bounce unsubscribes is a lot depends on the size of your
mailing list.  If your list has 200 members, its an indication something
is seriously wrong.  If it has 20,000 members then everything may be
just fine.

>> So you need to check your logs and find out if there is a some_site,
>> or more than one some_site which really doesn't like you.
>OK, I'll ask the server-admin/owner about the logs as I'm not sure where 
>they are or how to access them. Which logs specifically are we looking 
>for as I'm sure there are many?
>I assumed I would get an error message (email) for every time a posting 
>didn't reach the list but the latest "bounce action notification" I have 
>is from 5 months back, so apparently not. Maybe I've messed with some 
>settings in the Mailman web control panel as I kept getting so many of 
>them and didn't know what to do about it all.

What sort of mailman do you have?  What is the url for the
administrative interface?  What OS is it running under?  I only know
of some of the places you can find mailman logs, but if we can find out
what system you have and how it is set up and administered, then
somebody here will know where to look.

>> The usual reasons for disliking you are:
>> 1. We hate your IP, you have bad reputation with us, maybe you have been
>>     reported as a spammer someplace, or maybe you just send us a lot of
>>     mail and we don't like that.
>Again, this is the IP address of certain LIST-MEMBERS, right, and not my 

No, it is your server.

>Ouch! So it won't accept the email because my list-server PASSES ON a 
>message, and that IP address is obviously not the same as that of the 
>LIST MEMBER posting that message in the first place?


>> If this is your problem, and we think it is, you need a mailman
>> at least 2.16 and 2.18 is better.
>I'll contact my server-owner/admin to upgrade the Mailman software.
>I see from the Mailman site (http://www.list.org/) that version 2.1.20 
>is the latest version, and there's version 3.01 as well ("Show don't 
>tell", whatever that means).
>Is 2.18 the latest stable version?

No. The current stable GNU Mailman version are 2.1.20 released on 31-Mar-2015.

>I know many list-owners prefer to have messages reply back to the poster 
>of the message instead of the list itself (I've read those discussions 
>many times though I forget why), but for my list I'm sure this would 
>mean A LOT of list discussions done outside of the list, which in turn 
>defeats the purpose of my list (sharing information).

If you have your list configured so that reply-to goes to the list 
rather than to the sender, you will have a more difficult time of it,
but _things can be done_.

>> Does this make sense?
>Certainly more than a couple of days ago! Thanks for explaining :-)

Good luck.  


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