The Client Access server role is required in every Exchange server 2007/2010 organization.
The Client Access server role supports the Microsoft Outlook Web Access and Microsoft Exchange ActiveSync client applications and the Post Office Protocol version 3 (POP3) and Internet Message Access Protocol version 4rev1 (IMAP4) protocols. The Client Access server role also supports services, such as the Autodiscover service and Web services.
The Client Access server role accepts connections to your Exchange 2007/2010 server from a variety of different clients. Software clients such as Microsoft Outlook Express and Eudora use POP3 or IMAP4 connections to communicate with the Exchange server. Hardware clients, such as mobile devices, use ActiveSync, POP3, or IMAP4 to communicate with the Exchange server.
Failure of any of these protocols or issues in network connection between the clients and the server can disrupt client-server communication and cause critical emails to go undelivered. In order to avoid such adversities, the operations of the Client Access server should be continuously monitored, and administrators proactively alerted to abnormalities. This is where eG Enterprise helps administrators.