[Mailman-Users] massive unsubscribe

[Cyndi Norwitz]

On Sep 17, 2008, at 11:01 AM, Tecru Info wrote:

> We are having a problem where half the email list is getting  
> unsubscribed. Has this happened to anyone? The people did not  
> unsubscribe themselves.

Yes, this has happened to me.

I run several lists with Mailman at the same ISP.  One of the lists  
is not very active.  It will get bursts of activity then be dormant  
for weeks or a couple of months.  Every so often, I'll get massive  
unsubscribe notices.  Like 20 or 50 of them on a list with 300-400  
people.

I've spoken to my ISP about this and they say it's not people  
unsubbing themselves (well, of course they do that occasionally, but  
it doesn't account for the large numbers) and it's not an error.   
I've double checked records and it turns out that for every single  
person who was unsubscribed there was a notice to me that their email  
was bouncing (normal sorts of bouncing, nothing indicating spam).

It can take months for the bounce to translate to an unsubscribe.  My  
ISP thinks it's just that they're being processed all at a time,  
which makes sense.  That they're marked for unsubscribe and sit  
around for ages but then it all happens at once.  This may be  
triggered by a new post coming out and the subscribers bouncing one  
more time, but I'm not sure of that.

My other large list has daily traffic, so unsubscribes are spread out  
normally.

I don't know if this is what's going on with your list.

Cyndi