Communication compliance can scan email, Team, Yammer an other applications for policy matches such as bullying, conflicts of interest, fraud and regulatory compliance.
Customer Lockbox prevents Microsoft from accessing corporate content during a support ticket operation without explicit approval by administrators.
Information barriers restricts communication between certain people or departments. Prevent information sharing between trading and merger and acquisition teams, or between research departments and marketing.
Privileged Access Management is supported only in Exchange Online at the moment, but it prevents administrators from having standing permissions to perform certain actions without requesting elevation of privilege and approval. For instance creation or modification of journal rules that copy all messages to another email address can be prevented for Exchange administrators until they request and are granted approval.