What are the Planning considerations for Client Access Server Role?

The Client Access server role supports the Outlook Web Access, Outlook Anywhere, and Exchange ActiveSync client applications, in addition to the POP3 and IMAP4 protocols. The Client Access server role also hosts several key services, such as the Auto discover service and Exchange Web Services.

In order to have better client access functionality we have to perform a Planning consideration on Exchange Active Sync. Outlook web Access, outlook anywhere, POP3 and IMAP4 protocols and also securing client access.