Hey Ray,
Funny you should mention this.
I have several gmx accounts and some time ago, one account that I rarely used, was blocked for no apparent reason. I sure didn't send any spam or abuse their TOS.
So, I can't remember if I used this form or simply emailed support, either way I received a message with absolutely no explanation as to why the account was blocked.
I finally just gave up since it was an account I rarely used.
Wouldn't waste my time posting at their Facebook site.