password needed with every incoming Mail???

since two weeks with with every incoming mail I get an error “password needed”… it’s very, very annoying.
No changes are helpful…?!

Have you changed your password recently? Who is your email provider?

No, I have not changed my password. Before I never had problems with eM Client.
My email provider is gmx.net

Copy the text from the tab Logs in the Operations window after the error appears again and post it here. Thank you.