Refer to the Microsoft documentation for prerequisites and details on installing a clustered mailbox server. You must install the Active Clustered Mailbox role on the first node and install the Passive Clustered Mailbox role on the failover node.

Make sure that the same drive letter and path are available on all nodes and have adequate space for the installation. For example, if you install the Exchange program files in C:\Program Files\ExchSrvr on one node, you must install the files in C:\Program Files\ExchSrvr on all the other nodes. Use a drive letter on the local disk of each node in the cluster.

For requirements when installing Exchange Server on a secondary site for disaster recovery:

See Creating a parallel environment for Exchange Server on the secondary site.