Hi Benny,
From you description, you want to block a certain email which send a lot of spam to your side. Is it right?
Before moving on， I would like to confirm the detailed information about this issue.
1 Which Office 365 Plan are you using (P Plan, E Plan or A Plan)?
2 if you are receiving a lot spam emails from the same sender such as exilusj@inovativ.com or deferent sender?
If you are using E Plan or A Plan, you can manually setup FOPE on your side. We can configure the policy rules to block certain domain. Please refer to http://technet.microsoft.com/en-us/library/ff715218.aspx
Then, if you are using P Plan subscription and can’t configure FOPE on your side, you can also achieve your goal by adding the certain domain into blocked senders list in ECP (Exchange Control Panel).
For more details, please refer to Blocked Senders
Thanks,
Johnny