Old GMX account no longer works?

Today I restarted my old laptop to change my password with my old gmx email address for a game. But when I got to the inbox, there were no emails and a small triangle with an exclamation mark next to the synchronization button. It said I need to update my password or change the synchronization settings on my device.

Then a window opens where I can update the password, which I did. If I then save it and then it closes, nothing has changed…

Could anyone help me, please?

What does "old GMX account" mean? How old? How long has it not been used? It is quite possible that it was deleted.

So I couldn't log into the gmx website, aver on my laptop, I can't create a new account with the gmx either, because it says that it already exists, which is why I think it was not deleted.

GMX has meanwhile introduced that external email services such as Outlook and Microsoft's mail service can't easily access the mailbox. The POP3 and IMAP services are blocked. To change that, you have to set yourself to http://www.gmx.net and tick the appropriate box in your account settings.

I can't log in there because it says password or username is wrong. On my laptop, however, I was able to log into exactly with it… I can't create a new account, as it says that this email already exists

Have you ever tried to reset your password?

How does it work? About the website?

If you want to log in to the browser, enter your email address and then press "Forgot your password?" below the password entry.

Then it comes that my GMX does not exist… But if I try to create a new one with this name, it says that it already exists

https://hilfe.gmx.net/index.html

If you can access your old account from your laptop - and you do not confuse this with the old email data stored locally from an email program - then that simply means that you no longer know the correct password.