Our next focus is to ensure Active Directory (AD) is ready for Office 365. The purpose of this section is your readiness to synchronize AD with Office 365, leverage AD FS, and enable Exchange Federation.
To easily identify the necessary changes, run the Office 365 health, readiness, and connectivity checks tool at https://portal.office.com/tools. Be sure to run this tool from a Windows-based workstation, while connected to the same Active Directory forest and Exchange Organization that you will be connecting to Office 365.
Launch the tool and select both the Quick and Advanced check boxes, and then click on Next to run the checks as shown in the following screenshot. Also, you may have to install some desktop components for Office 365. These components may include the Azure Active Directory Sign-in Assistant and the Azure Active Directory Module for Windows PowerShell:
By running this tool, we will uncover key changes that may be necessary...