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

[Jayson Smith]

Hi,

The problem isn't with Mailman receiving unwanted messages. The problem 
is that Mailman is trying to deliver outbound messages, and is having 
problems, messages are being returned as undeliverable. Everything in 
Mailman is working properly up to the point where messages are being 
bounced. This could be for a number of reasons. Some users might have 
outdated addresses, in which case messages would be bounced back with 
errors similar to "No such user" or "User unknown." Some people may have 
full mailboxes. But the more likely problem, since you're having many 
issues come up all at once is that there's a problem between your server 
and the destination mail server for those messages. It could be that the 
DMARC settings in Mailman aren't set correctly and those servers are 
rejecting messages they don't like, or it could be that your server's IP 
address has somehow received a bad reputation, and certain mail servers 
will reject all mail from your server, regardless of sender, recipient, 
or content.

Jayson

On 12/13/2015 7:42 AM, Hal wrote:
> On 13/12/2015 13:05, Jayson Smith wrote:
>> Hi,
>>
>> Unfortunately, disabling automatic removal from the list will only fix
>> one effect of the problem, not the problem itself. There's something
>> going on which is causing mail to those addresses to bounce. If you are
>> receiving messages with the subject of "Bounce action notification"
>> these will tell you who is bouncing mail, and the attached mail delivery
>> failure reports will tell you why they are bouncing mail, which is
>> important. I suspect you have a DMARC or IP reputation issue.
>
> I'm not sure I fully understand this and what to do about it.
>
> Are you saying that even though I turn "automatic removal" off I will 
> still have postings from certain list members NOT reaching the list 
> (but bouncing with an error message back to me, the list owner 
> -possibly also with an error alert to the poster as well)?
>
> Are there other restrictions in the Mailman software which stops 
> postings based on other criteria? If yes, can this/these features be 
> turned off so in the end I only rely on "only allow posting from 
> existing members"? I assume having the latter enabled will at least 
> prevent automated spam messages from reaching the list.
>
> Alternatively I'm guessing the solution is to set the list to 
> moderation and approve every single message manually. I do have a 
> relatively low-volume list, so this is doable (but not something I 
> would enjoy enabling) -how is this done actually? By logging into the 
> administration interface and clicking on something for every message, 
> or can it be done simpler/quicker by simply pressing reply to a 
> certain admin message or something?
>
>
>
> Hal
>
>
>