Note
Access to this page requires authorization. You can try signing in or changing directories.
Access to this page requires authorization. You can try changing directories.
APPLIES TO: 
2016 
2019 Subscription Edition
Tip
Looking for what's discontinued in Exchange Server 2016? See What's discontinued in Exchange Server 2016.
This topic discusses the components, features, and functionality that's been removed, discontinued, or replaced in Exchange 2019.
Discontinued features from Exchange 2016 to Exchange 2019
This section lists the Exchange 2016 features that are no longer available in Exchange 2019.
Architecture
| Feature | Comments and mitigation |
|---|---|
| Unified Messaging (UM) | Unified Messaging has been removed from Exchange 2019. We recommend that Exchange 2019 organizations transition to Skype for Business Cloud Voice Mail. |
Discontinued features from Exchange 2013 to Exchange 2019
This section lists the Exchange 2013 features that are no longer available in Exchange 2019.
Architecture
| Feature | Comments and mitigation |
|---|---|
| Unified Messaging (UM) | Unified Messaging has been removed from Exchange 2019. We recommend that Exchange 2019 organizations transition to Skype for Business Cloud Voice Mail. |
| Client Access server role | Client Access services that run on the Mailbox server role replaced the Client Access server role. The Mailbox server role now performs all functionality that was previously included with the Client Access server role. For more information about the new Mailbox server role, see Exchange Server architecture. |
| MAPI/CDO library | The MAPI/CDO library was replaced by Exchange Web Services (EWS), Exchange ActiveSync (EAS), and Representational State Transfer (REST) APIs. If an application uses the MAPI/CDO library, it needs to move to EWS or EAS to communicate with Exchange 2019. |
De-emphasized features in Exchange 2019
The following features are being de-emphasized in Exchange 2019 and may not be included in future versions of Exchange.
Third-party replication APIs
RPC over HTTP
Database availability group (DAG) support for failover cluster administrative access points