I do get your point. I've got the same problem with the CheckUser-l mailing list. Even though we removed the option to subscribe on our general information page and we automatically reject emails from non-members, we still get dozens of spam via the -owner address. And I have no idea what we can do about it. There is no such option to block spam to -owner.
Van: Listadmins <listadmins-bounces(a)lists.wikimedia.org> namens Maarten Dammers <maarten(a)mdammers.nl>
Verzonden: vrijdag 5 mei 2017 10:54:12
Onderwerp: Re: [List admins] Removed myself as owner of the pywikibot* mailman lists
You all seem to miss the point. The junk that got through was directed at the -owner addresses like pywikibot-owner(a)lists.wikimedia.org<mailto:firstname.lastname@example.org> not at the actual lists.
For quite some time I have been one of the people maintaining and
moderating the different Pywikibot mailman lists. Over time the amount
of junk (spam) coming in through the -owner addresses of these lists has
increased a lot. My impression is that the people in charge of
maintaining mailman are not doing enough to fight this kind of abuse.
I'm so annoyed by this I decided now is a good time to stop maintaining
mailman lists and spend my time on something more fulfilling.