Our next focus is to ensure Active Directory (AD) is ready for Office 365. The purpose of this section is to check your readiness to synchronize AD with Office 365, leverage ADFS, and enable Exchange Federation.
To easily identify the necessary changes, run the Microsoft Office 365 Readiness Tool (http://community.office365.com/en-us/f/183/p/2285/8155.aspx#8155). By running this tool, we will uncover the key changes that may be necessary to leverage the service. Once you run this tool, you will be able to identify the potential issues or changes required for:
Forest/domain structure and Exchange schema
Active Directory users, contacts, and group objects and single sign-on