GMX IMAP synchronisation fails

[cyberzork]

See this thread that might help you

2-Factor GMX.net with app specific password "Authentification failed"

Hey I have a weird problem with my GMX.net account and eM Client. My problem: Everytime I start eM Client, I get the following error message from the GMX.net Account with a prompt to enter the password: Server says "authentification failed" I will give in the app specific password I created in the GMX.net online portal, because my 2-Factor is activated. And it will run like a charm… till the next eM Client start. Then I will get the error message again. My workaround, use …