Can´t Register on GPotato

Hey guys ..

i have a big problem .. evertime i want to register myself on GPotato.eu .. the Site says that my Email is incorrect or not avaible..

Can someone help me with this problem ..

I have already choosen emails on web / hotmail / googlemail and spambog. but all dont work.
´
mfg Angel

I have me regestry with a e-mail on yahoo.de without problems