New in Exchange 2016
There are a number of new features introduced in Exchange 2016
Outlook on the Web
Outlook on the Web is the rebranded new version of OWA. It has an improved look-and-feel and works smoother than before. Outlook on the Web is also the primary email client for Exchange Online. This is the client that is controlled by the Exchange development team, and a lot of effort is put into Outlook on the Web.
Strongly related to Outlook on the Web is another server role called Office Online Server 2016, the successor of Office Web Apps server 2013. This server is used by Exchange to render Office attachments for use in Outlook on the Web
Simplified Architecture
The simplified architecture is Microsoft’s way to enforcing the Preferred Architecture to this new version. It means that by default the old Client Access server role and Mailbox server role are now combined into only one server role, the Exchange 2016 Mailbox server role. Under the hood it’s nothing more than the old multi-server role, but it is now enforced.
MapiHttp as the default protocol
MapiHttp is now the default protocol for Outlook clients to connect with Exchange 2016, and Outlook Anywhere is now deprecated. MapiHttp is much more efficient than Outlook Anywhere, it is more stable when working with flaky Wifi networks and starting up the Outlook client is much faster compared to Outlook Anywhere
Auto Expanding Archives
You start with a 100GB Archive Mailbox, and at one point when this Archive Mailbox reaches its limit, it is automatically increased with 50GB increments (it actually adds another 50GB Archive Mailbox).
Storage Improvements
Just like previous version, Microsoft has made some improvements to the way ESE (Extensible Storage Engine, i.e. the database engine in Exchange) is working. But it is not only the ESE improvements, Microsoft now also recommends using the ReFS (Resilient File System) instead of NTFS. ReFS was already supported in Exchange 2013, but it is now a recommended solution.
Integration with Office 365
Exchange 2016 is even further integrated into Office 365. When you have a hybrid environment more options are available then when you have a pure on-premises environment. Look at features like Exchange Online Protection (ok, this is available in a stand-alone environment with Exchange on-premises as well), the new Compliance Center or Modern Attachments.
Coexistence scenarios
Since Exchange 2013 and Exchange 2016 are so close together, coexistence between the two is very, very easy. Unlike previous versions, Exchange 2013 Client Access can proxy requests to Exchange 2016 Mailbox, and of course Exchange 2016 can proxy requests directly to Exchange 2013. This up-version proxy makes integration between the two very easy. Just add Exchange 2016 servers to an existing, load balanced array of Exchange 2013 Client Access server and continue working. It doesn’t matter where the user’s Mailbox is located, it is fully transparent. The client experience matches the version of the Mailbox server where the Mailbox is located.
Deprecated in Exchange 2016
New versions come with new features, and at the same time a new version is used to cut old features, or deprecate them. This is a small list of features that are not available or deprecated in Exchange 2016:
Support for Outlook 2007
Support for Exchange 2007
Outlook Anywhere
Client Access server role
MAPI/CDO









