Architecture – Server Roles .
Exchange 2016 has reduced the number of server roles to two: The Mailbox and Edge Transport server roles with the Edge Transport being optional.
In combining the client access server, hub transport roles into the mailbox role, this means Exchange servers in the environment can be the same hardware. This change will likely mean a reduction in the number of exchange servers and cost to licenses such as Windows license, exchange licenses, storage, power etc. This in turn reduces the effort to monitor, patch and support the Exchange servers.
Active Sync Onboarding to office 365
Previously in a hybrid environment when a mailbox is moved to exchange online the end user would have to reconfigure their mobile device.
Since Exchange 2016, Exchange Server 2013 Cumulative Update 8 (CU8) and Exchange Server 2010 SP3 Rollup Update 9 (RU9) the end user no longer has to reconfigure their active sync (mobile) device. The TargetOwaURL is used for redirection.
This makes migration to office 365 a less disruptive process for users especially those remote/not office based. Previously a user would have to manually configure their mobile device once their mailbox was moved to office 365. The end user would have to make note/print out instructions to follow the setup process depending on their device (Android/iPhone/Windows Mobile) this could be different depending on the device and model. Today where almost everyone has one or more devices, this new update removes the time-consuming exercise of reconfiguring end user mobile devices. Once connected and reconfigured the mobile device no longer looks for the exchange server and connects directly to exchange online
There are some unsupported scenarios.
o Mailboxes moved from Exchange Server 2007 to Office 365. These will need to be manually updated.
o Mailbox moves from Exchange Online to back to on-premises.
o Cross forest mailbox moves between two Exchange Server 2013 or Exchange Server 2010 organizationsMobile devices or applications that do not process HTTP 451 redirects. These will require manual setup (i.e. Outlook App)
Rather than in previous versions of Exchange On-Premise the hybrid configuration wizard for office 365 is now cloud based. When choosing Hybrid deployment in Exchange 2016 you will download and install the hybrid application wizard. Now the Hybrid configuration is a standalone application it is no longer tied to the exchange on-premises exchange version. This gives an Up-To-Date hybrid experience as the hybrid configuration wizard will download the latest version every time it is run. Meaning any improvements or fixes are available and not dependant on exchange downtime as the latest cumulative update is installed.