Info: Review requirements for multi-forest hybrid deployments With Exchange 2016 SP1, hybrid deployments are supported when ...

Info: Review requirements for multi-forest hybrid deployments With Exchange 2016 SP1, hybrid deployments are supported when your organization has multiple on-premises Active Directory forests and a single Office 365 organization. Multi-forest organizations are defined as organizations having Exchange servers deployed in multiple Active Directory forests. Organizations that have a resource forest for user accounts, but maintain all Exchange servers in a single forest, aren't classified as multi-forest in hybrid deployment scenarios. These types of organizations should consider themselves a single forest organization when planning and configuring a hybrid deployment. Learn more at Hybrid deployments with multiple Active Directory forests. Learn more.