Block and Allow Sender List
So it appears though there isn't a basic feature that exists within office 365 admin (Exchange or MSC) that allows you to Block & Senders without being Policy dependent. The two places where Allow & Block senders List that are available, are unfortunately policy dependent or have a character limit.
1) Mail flow transport rules - there's a character limit, so if a medium/Large organisation were to make most of this, they wouldn't able to!
2) Antispam policy - according to some of the MSFT docs, there's a limit of around 1000 domains/sender lists that could be added, which I suspect (correct me if I'm wrong), is dependent if the email get's triggered by an Antispam policy.
Are MSFT releasing (or do they have) a basic allow and block domain/sender list feature - that isn't policy dependent & has no domain/character limit?
