Two basic deployment scenarios are covered: the single-server scenario and a multiserver scenario.
In the single-server scenario, there is only one Exchange server. Users connect directly to Internet Information Services (IIS) on the single Exchange server and access their mailboxes on the Exchange server. In this configuration, the Mailbox server role and the Client Access server role are both installed on a single server. Many smaller environments will use this topology. This is also the most simple and straightforward approach to implementing OWA.
There are no limitations inherent in this scenario. All protocols, including POP3 (Post Office Protocol version 3), IMAP4 (Internet Messaging Application Protocol ...