Client Access Server
The Client Access server is one of the most important server roles in any Exchange environment. As someone from Microsoft 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 Internet. And whether they are Outlook clients or browser-based clients, or POP3 and IMAP4 clients, all clients connect to the Client Access server and then are routed ...