[Mailman-Users] Understanding patterns of unsubscribe

Robert Heller heller at deepsoft.com
Tue Dec 23 00:48:44 CET 2014

At Tue, 23 Dec 2014 09:53:13 +1100 "Steven D'Aprano" <steve at pearwood.info> wrote:

> Hi all,
> Back in September, I migrated an announcement-only mailing list from 
> Yahoo to mailman, with approximately 1800 email addresses. An unknown 
> number of these were dead.
> The mailing list I am running sends out one, maybe two, emails a month, 
> at around the same time of the month. It's not a discussion list, so 
> there are no replies from subscribers.
> I expected that the first month, there would be a lot of automatic 
> unsubscriptions, as the dead addresses were noted and removed, and then 
> in subsequent months there might only be a trickle of automatic 
> removals. To my surprise though, there has been a steady pattern of mass 
> unsubscriptions each month, around 100-200 each month following the 
> posted announcement.
> I'm not sure whether this is normal (if it is, unless the number of 
> unsubscriptions begins to fall soon, I'll soon be left with no 
> subscribers) or whether I'm doing something wrong.

Are these mass removals automatic or manual? That is, is the list doing this 
or are your subscribers doing it?

Some notes:  

1) What are you doing about DMARC, DKIM, and ADSP? Remember, *Yahoo* has a strict
reject DMARC policy. Of course this really kicks in if a Yahoo person posts.
It *you* are the only poster and are posting from a non-Yahoo address (that is
from a domain that does not have a strict reject DMARC policy), then this does
not apply.

2) YahooGroups *does not* (AFAIK) send out monthly reminders. Mailman does.  
Your Yahoo users might be thinking the Mailman monthly reminder is some sort 
of robotic spam message and rejecting it.

2) It is possible that many of your Yahoo users are actually alive and well, 
but that YahooGroups suspended mail delivery of the YahooGroups mailings. Now 
that you switched to Mailman, these users are 'suddenly' getting these 
messages from a mailing list they have completely forgotten about.

> Here are my bounce processing settings:
> bounce_processing = Yes
> bounce_score_threshold = 4.0
> bounce_info_stale_after = 65
> bounce_you_are_disabled_warnings = 3
> bounce_you_are_disabled_warnings_interval = 10
> Remembering that I only send out 1 or 2 emails every 30 days (give or 
> take a couple of days in either direction), does this seem reasonable? 
> Or is my bounce processing too strict?
> Thanks in advance,

Robert Heller             -- 978-544-6933
Deepwoods Software        -- Custom Software Services
http://www.deepsoft.com/  -- Linux Administration Services
heller at deepsoft.com       -- Webhosting Services

More information about the Mailman-Users mailing list