[Mailman-Users] "Bounce action notification" emails for subscribes/unsubscribes

[Mark Sapiro]

On 9/18/17 1:20 AM, Stephen J. Turnbull wrote:
> Terry . writes:
> 
>  > Sorry for the delay in responding, and thanks for your generous
>  > offer of working with my webhost and/or cPanel to solve this.  I
>  > passed that offer to my webhost, but it seems they have been able
>  > to sort it out with cPanel themselves.
> 
>  > I then tested lists in all 7 domains, and they all sent
>  > subscribe/unsubscribe emails to me perfectly.  I then asked Jim
>  > Dory (who has participated in this thread) to setup a default
>  > address for his list, and it worked for him, too.
> 
> Great!!


Yes. The bottom line here seems to be that things are now working as
they should be, so the issue seems to be solved.


> 
>  > ==========================================
>  > The issue with @mydomain.com was caused due to the setting "Discard
>  > the email while your server processes it at SMTP time with an error
>  > message" under cPanel>>Email>>Default Address. We've setup "Forward
>  > to Email Address" to
>  > catchall at mydomain.com<mailto:catchall at mydomain.com>.  As cPanel
>  > support explained, this indicates that all mail that is delivered,
>  > but does not have an address (like mailman-bounces@) on this server
>  > will be delivered to the default account - this can potentially
>  > pose the risk of the email account receiving email for accounts
>  > that do not exist, something commonly seen when a domain is being
>  > spoofed.  Otherwise, it will be rejected with "No such user here".
>  > ==========================================
> 
>  > I’m confused by the wording of the above paragraph from the
>  > webhost, but maybe they mean that the server is configured to not
>  > allow emails to be sent out *from* addresses which can’t receive
>  > emails, and this is to help reduce outbound spam.


I'm confused too. Perhaps something got lost or confused in transmission
from cPanel via the web host, or perhaps this is some unusual cPanel
thing that we don't understand. We may never understand "why" this fix
works, but as long as it does work, we can be happy about that.


...
> 
>  > So, I guess when Mailman tries to send a subscribe/unsubscribe
>  > notification email out from
>  > mailman-bounces at mydomain.com<mailto:mailman-bounces at mydomain.com>
>  > to the list owner address, maybe the server blocks it, since that
>  > mailman-bounces at mydomain.com<mailto:mailman-bounces at mydomain.com>
>  > address doesn’t exist, as such.


There is a 'mailman' list and as such, the mailman-bounces address
should be deliverable, but cPanel does things in a strange way. Most
lists are associated with a domain - perhaps one of several domains
hosted on the server. Exim is configured to know this, so that mail to
yourlist at yourdomain actually gets delivered to a list named
yourlist_yourdomain and mail to otherlist at otherdomain is delivered to a
list named otherlist_otherdomain. This is how cPanel handles multiple
domains without requiring listnames to be globally unique.

However, the 'mailman' list is different. It's internal name doesn't
have a '_domain' suffix so the list 'mailman' exists, but
'mailman_yourdomain' does not.

I suspect cPanel may have had some Exim magic to deal with this that got
lost or broken in a cPanel update. That might explain things.

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