Sorry for the Spam, i'm Working on it -.-
Running hMailServer, and looking at the moment how they got in. Send ca more than 180k messages in 2-3 days.
Deactivated for Tests all Domain Accounts, still sending...
Found the Weak account.
Clearing all the other Accounts out, so that i only have the Accs i really need.
Found out that i also need to clear the Delivery queue, waiting for 6712 messages to disapear.