On Sat, Oct 10, 2020 at 10:57:26AM +0200, c.buhtz@posteo.jp wrote:
> There is a "Sender:" header entry I can filter on.
> 
> But I do not setup anything because I don't case the problem.

I don't unerstand this sentence.

> Btw: It is nice that all of you using Gnus and (maybe) a local
> mailserver with powerfull filtering. I don't.

FWIW, I'm using mutt (I plan to switch to gnus some day, but that's
irrelevant).

> It is kind of a religious problem. :D

Fine. You keep your religion, others keep their religions. Don't try
to force your religion on me: I might turn nasty.

> Isn't there a setting on the mailinglist site (e.g. mailman) that can
> handle problems like this?

I made myself quite a bit of work to explain to you what you can do.
Even with a link to mailman docs on how you can set your subscription
settings.

Do you read the responses you receive?

Cheers
 - t