Exchange 2013 Client Access Server
The Client Access server role is the most important role in any Exchange deployment because it provides access for all mail clients to the mail data. Without a Client Access server you will have no access to your data. As someone from the Microsoft Exchange product group once said during a conference, “You can have the most beautiful and redundant Mailbox server environment with a DAG and everything, but without a Client Access server you cannot access it and it’s useless.”
And that's true. The Client Access server is used by all clients, whether they connect from the internal network or from the ...