Microsoft Exchange 2007 Server with CAS Role

OWA 2007 and OWA Extension are supported for Exchange Server 2007 SP1 with Client Access Server (CAS) Role on both Windows Server 2003 and 2008. The CAS Role basically accepts connections from a variety of clients to allow them access to the Exchange Server infrastructure. To some extent, the CAS Role shares some similarities with the old front-end (FE) servers in Exchange 2000 and 2003.

Microsoft Exchange 2007 Server Types

Microsoft Exchange 2007 Server types are much different than previous versions of Exchange. OWA Extension can only be installed on Exchange Servers with CAS role as shown in Figure 1 above. An Exchange Server may also be configured as both a CAS role and a Mailbox server, as described in “OWA Extension Supported Configurations” section later in this document.

Exchange 2007 server types are listed below:

Client Access Server (CAS) Middle-tier server that supports Microsoft Outlook Web Access (OWA), Microsoft Exchange ActiveSync, and Outlook Anywhere client applications, and the POP3 and IMAP4 protocols. CAS also hosts Exchange Web Services. This server does require installation of both OWA 2007 and OWA Extension.

Mailbox Server Back-end server that can host mailboxes and public folders. This server does not require installation of OWA 2007 and OWA Extension.

The following Exchange 2007 server types are not relevant to OWA Extension and are only mentioned in the interest of completeness:

Unified Messaging Server Middle-tier server that combines voice messaging, fax, and e-mail messaging into a single messaging infrastructure. This server does not require installation of OWA 2007 and OWA Extension.

Hub Transport Server E-mail routing server that routes e-mail within the Exchange organization. This server does not require installation of OWA 2007 and OWA Extension.

Edge Transport Server E-mail routing server that typically sits at the perimeter of the topology and routes e-mail into and out of the Exchange organization. This server does not require installation of OWA 2007 and OWA Extension.

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