Hello,
ok, my fault. But for all others, specially the german ones where the german translation is not that clear, you have also to write an valid email address in the fields of system/config/main-email:
-> E-Mail Adresse für Zahlungsbestätigung
-> E-Mail Adresse für Bestellbestätigung
I don't know why I have to write an email address here also because in the email its own there are the right addresses automatically. But they would not be send as long as you put those email addresses also in the above mentioned fields.
Regards, Benny.