An offline address book is a copy of a user address book that can be downloaded and used in an offline environment. In this course, you’ll explore offline OABs in Exchange Server 2019 and Exchange Online, including how to create, use, and manage them. You’ll start by examining the fundamentals of OABs, as well as OAB generation and the Mailbox Assistant. You’ll then explore the OAB distribution process, planning a deployment, and moving OAB generation to another server. Next, you’ll see how to download OABs using Outlook and how to use PowerShell to create an OAB. You’ll continue on to see how to add and remove address lists from OABs and how to change the default OAB using Exchange Online PowerShell. You’ll learn how to assign an OAB to users and how to remove an OAB using Exchange Online PowerShell. Lastly, you’ll see address book policies, including how to create them using the Exchange Management Shell. These topics will help prepare you for the MS-201 Implementing a Hybrid and Secure Messaging Platform certification exam.