The title of this white paper notwithstanding, Osterman Research wants to make it clear at the outset that we believe Microsoft Office 365 to be a robust and capable platform, one that will serve most organizations well. If your organization is using Office 365, we recommend you continue to do so. If you’re not using it, we recommend you consider it. Microsoft offers a large, varied and growing number of features and functions in Office 365, and at a wide range of price points that will satisfy a number of different markets.That said, decision makers evaluating the efficacy of Office 365 to meet their business requirements must be aware of its shortcomings in the areas of data protection, archiving, security, encryption, authentication and eDiscovery (among others) covering workloads like Exchange Online, SharePoint Online, OneDrive for Business, Skype for Business, and Azure Active Directory. An awareness of these shortcomings enables decision makers to plan for the mitigations required to assure the proper business performance of Office 365