@girish That works great! Many many thanks for you prompt support!
I did a clean installation and restored a backup.
Since than, everything is working fine.
Yeah, I found this exact same spam text in another forum.
@girish Thanks, I thought maybe I set the DNS wrong but it must be the host then
@nebulon You try to make things easy for us but we'll screw it up somehow. ; )
@girish Thank you girish