How to disable Client Forwarding Rules To External Domains in Office 365/Exchange

**2019 UPDATE - The automatic way to apply this rule has been removed. You now have to make the rule manually. Client forwarding rules is a common method for data breaches in Office 365. What they do is make every email that is received by an Office 365/Exchange mailbox get forwarded to an external party. This setting is available automatically in the Office 365 Enterprise SKUs via Microsoft 365 Security & Compliance Center but you can also set it up manually in EAC (Exchange Admin Center).