Can't send E-Mail to factory@lists.opensuse.org

I’m receiving since many years the list of factory, project and users-de @lists.opensuse.org

I tried to answer to some questions and none of my emails gets through. Translated from German: Error while transmitting the message. The remote host has closed the connection. In German: Fehler beim Übertragen der Nachricht. Der entfernte Rechner hat die Verbindung geschlossen

Well, I signed off an on again, no success. Any ideas?

Can you log in here:
https://lists.opensuse.org/archives/

Well, I subscribed for this list years ago and an account at lists.opensuse.org wasn’t necessary. So ok, I signed up there this morning and still my e-Mails don’t get delivered, even after waiting for an hour. So strange…

Solved the issue. I’ll try to translate from German:
kmail options => accounts (Zugänge) => “send” tab (Versand) => change (Ändern) => Advanced options (Erweiterte Einstellungen) => send userdefined computer name to server (Benutzerdefinierten Rechnernamen zum Server senden), I chose the email address for that field and now my emails no longer get rejected.