You can choose from default categories to block. It is under policy, non standard rules. I can setup setting called Interned and Email and there is access to web pages. (I am translating names, because my cloud administrator panel is in Polish). So under this is setting called categories which contains "default blocking" and there is setting "communication and social networks". This setting blocks whole email providers like gmail.com yahoo etc. it also blocks office.com, and i want to exclude office365 from this rule.