Office 365 Built-In Security
Office 365 is a security-hardened service, designed following the Microsoft Security Development Lifecycle. Microsoft bring together the best practices from two decades of building enterprise software and managing online services to give you an integrated software-as-a-service solution.
At the service level, Office 365 uses the defense-in-depth approach to provide physical, logical, and data layers of security features and operational best practices. In addition, Office 365 gives you enterprise-grade user and admin controls to further secure your environment.