Server Roles in Exchange 2013 Hybrid Deployments
Applies to: Exchange Server 2013
Topic Last Modified: 2013-05-17
When configuring a hybrid deployment in an Exchange Server 2013 organization, you don't have to install any additional Exchange servers in your existing Exchange organization. Your Client Access and Mailbox servers coordinate communications between your existing Exchange 2013 organization and the Exchange Online organization. This communication includes message transport and messaging features between the on-premises and Exchange Online organizations. We highly recommend installing more than one Exchange server in your on-premises organization to help increase reliability and availability of hybrid deployment features.
Here is a quick overview of the Exchange 2013 server roles in a hybrid deployment:
- Client Access server role The Client Access server role continues to provide essentially the same functionality typically provided by Client Access servers in your Exchange 2013 organization with a few additions required to support a hybrid deployment. The Client Access server also handles all secure mail messages sent between the on-premises and the Exchange Online organizations, as well as handling transport rules, journaling policies, and message delivery to user mailboxes in a hybrid deployment. By default, a dedicated Receive connector is configured on the Client Access server to support secure hybrid mail transport. All client connectivity, including Outlook client access, Outlook Web App, and Outlook Anywhere goes through the Client Access server role. Organization relationship features between the on-premises and Exchange Online organizations, such as free/busy sharing, are also handled by the Client Access server role.
Learn more at Client Access Server.
- Mailbox server role The Mailbox server role hosts the on-premises recipient mailboxes and communicates with the Exchange Online organization by proxy via the on-premises Client Access server. By default, a dedicated Send connector is configured on the Mailbox server role to support secure hybrid mail transport.
Learn more at Mailbox Server.
Depending on the hybrid deployment configuration that you want, an Exchange 2013 server requires one or both of the server roles to be installed on it:
- Single Exchange server If you choose to install a single Exchange server in your on-premises organization, you’ll need to install both the Client Access and Mailbox server roles on the single server.
- More than one Exchange server If you choose to install more than one Exchange server in your on-premises organization, you can install the server roles on separate servers in your on-premises organization. For example, you could install one Exchange server that has the Mailbox and Client Access roles installed and also install another Exchange server that has only the Client Access server role installed. However, the best practice and recommended server configuration is to install both the Client Access and Mailbox server roles on each server deployed in your on-premises organization.
Learn more about Exchange capacity planning at Understanding Multiple Server Role Configurations in Capacity Planning.
Exchange servers provide several important functions for your on-premises organization in a hybrid deployment:
- Federation Exchange servers enable you to create a federation trust for your on-premises organization with the Microsoft Federation Gateway. The Microsoft Federation Gateway is a free, cloud-based service offered by Microsoft that acts as the trust broker between your on-premises organization and the Office 365 tenant organization. Federation is a requirement for creating an organization relationship between the on-premises and the Exchange Online organizations.
Learn more at Federation.
- Organization relationships Exchange servers with the Client Access server role enable the creation of organization relationships between the on-premises and Exchange Online organizations. Organization relationships are required for many other services in a hybrid deployment, including calendar free/busy information sharing, message tracking, and mailbox moves between the on-premises and Exchange Online organizations.
Learn more at Sharing.
- Message transport Exchange servers with the Client Access and Mailbox server roles are responsible for message transport in a hybrid deployment. Using Send and Receive connectors, they serve as the connection endpoints for incoming external messages and also provide outbound message delivery to the Internet and the Exchange Online organization.
Learn more at Transport Options in Exchange 2013 Hybrid Deployments.
- Message transport security Exchange servers with the Client Access and Mailbox server roles help to secure message communication between the on-premises and Exchange Online organizations by using the Domain Security functionality in Exchange 2013. Security can be increased by using mutual transport layer security authentication and encryption for message communications.
Learn more at Understanding Domain Security.
- Outlook Web App Exchange servers with the Client Access server role support configuring a single URL endpoint for external connections to on-premises and Exchange Online mailboxes. For on-premises mailboxes, Client Access servers are configured to service Outlook Web App requests. For Exchange Online organization mailboxes, Client Access servers are configured to automatically display a link to the Outlook Web App endpoint on the Exchange Online organization.
Learn more at Outlook Web App.
If you choose to add additional Exchange servers to support your hybrid deployment, the Exchange server is deployed much like any other Exchange 2010 server is deployed to your existing Exchange 2013 organization. Configuring your existing on-premises Exchange 2013 organization for a hybrid deployment doesn’t require any special Exchange server topology. The following table describes briefly the changes in services after configuring a hybrid deployment.
|Service||Before hybrid deployment||After hybrid deployment||Description|
Message transport (inbound and outbound)
Exchange 2013 Client Access server
Exchange 2013 Client Access server or Exchange Online Protection (EOP) included with Office 365
The MX (mail exchanger) record for the domain may remain unchanged or be updated to point to EOP.
Outlook Web App public URL
Exchange 2013 Client Access server
Exchange 2013 Client Access server
Client Access servers continue to handle Outlook Web App requests for on-premises mailboxes. Outlook Web App requests for mailboxes hosted on Exchange Online are provided with a link to the Exchange Online Outlook Web App URL.
Exchange 2013 enables hybrid deployment functionality with the Hybrid Configuration wizard. You can use any Exchange 2013 media when installing additional Exchange 2013 servers.
You can get Exchange 2013 at Download Microsoft Exchange Server 2013.
|You need to provide an Exchange 2010 Hybrid Edition product key on the hybrid server when you configure a hybrid deployment with Office 365. To obtain a Hybrid Edition product key, contact Office 365 support.|