Mailbox backup is supported for Microsoft Exchange Server 2010 Service Pack 1 (SP1) and later.
Mailbox backup is available if at least one Agent for Exchange is registered on the management server. The agent must be installed on a machine that belongs to the same Active Directory forest as Microsoft Exchange Server.
Before backing up mailboxes, you must connect Agent for Exchange to the machine running the Client Access server role (CAS) of Microsoft Exchange Server. In Exchange 2016 and later, the CAS role is not available as a separate installation option. It is automatically installed as part of the Mailbox server role. Thus, you can connect the agent to any server running the Mailbox role.
To connect Agent for Exchange to CAS
If no Agent for Exchange is registered on the management server, the software suggests that you install the agent. After the installation, repeat this procedure from step 1.
In Exchange 2016 and later, the Client Access services are automatically installed as part of the Mailbox server role. Thus, you can specify any server running the Mailbox role. We refer to this server as CAS later in this section.
As a result, the mailboxes appear under Devices > Microsoft Exchange > Mailboxes.