Masaru, et al --

...and then Masaru Nomiya said...
% 
% In factory ML and buldservice ML, there exist ham mails with
% X-MailFrom: bar@gmail.com.
% So, I changed the script as follows;
...
% 
% 	:0 
%  	unsure/.
% }

Yes, that's a better answer.  Sadly, the best you can do is "we can
isolate hyperkitty-interface posters".  That may be enough for you even
if it doesn't solve the general problem (which I agree is messy).

But YAY to find something that works at least enough.  It's a start :-)

You simply have to flag on two strings:

  User-Agent: HyperKitty on https://lists.opensuse.org/
  From:  *@gmail.com

The current wave of spammers match on both. But there are also honest users which match the same criteria. I could post here easily, on this thread, and match.

-- 
Cheers / Saludos,
               
		Carlos E. R.

  (from Elessar, using openSUSE Leap 15.5)