I don’t think you can host your .de domain with us.
Even though you can point the domain name to our servers, our servers don’t know which account and website that domain name is related to. To do that, you need to add the domain to a hosting account. And to add the domain to a hosting account, you must change the nameservers of your domain to point to our servers first.
The .de extension is specifically listed in our article about “annoying domain extensions which are really picky about nameservers”: