Applies to: Exchange Server 2007 SP3, Exchange Server 2007 SP2, Exchange Server 2007 SP1, Exchange Server 2007
Topic Last Modified: 2006-06-13

In previous versions of Microsoft Exchange Server, administrators were offered limited choices on what features could or could not be installed. For example, in Exchange Server 2003 and Exchange 2000 Server, the setup process installed all features regardless of which features the administrator planned to use. This behavior required the administrator to turn off or disable the undesired features.

Because organizations tend to group their management tasks around a core set of server roles, Exchange Server 2007 maps Exchange Server management to this more natural way of doing things. System management in Exchange 2007 fundamentally shifts the administrative experience for deploying and managing servers to focus on server roles.

Overview of Server Roles

A server role is a unit that logically groups the required features and components needed to perform a specific function in the messaging environment. The requirement of a server role is that it is a server that could be run as an atomic unit of scalability. A server role is composed of a group of features.

Server roles, the primary unit of deployment, enable administrators to easily choose which features are installed on an Exchange server. Logically grouping features in server roles offers the following advantages:

  • Reduces attack surface on an Exchange server.

  • Allows you to install and configure an Exchange server the way you intend to use it.

  • Offers a simple installation, and the ability to fully customize a server to support your business goals and needs.

Exchange Server 2007 Server Roles

Exchange Server 2007 includes the following server roles:

  • Mailbox Server   This is a back-end server that can host mailboxes and public folders. For more information about the Exchange 2007 Mailbox Server role, see Mailbox.

  • Client Access Server   This is the middle-tier server that hosts the client protocols, such as Post Office Protocol 3 (POP3), Internet Message Access Protocol 4 (IMAP4), Secure Hypertext Transfer Protocol (HTTPS), Outlook Anywhere, Availability service, and Autodiscover service. The Client Access Server also hosts Web services. For more information about the Exchange 2007 Client Access Server role, see Client Access.

  • Unified Messaging Server   This is the middle-tier server that connects a Private Branch eXchange (PBX) system to Exchange 2007. For more information about the Exchange 2007 Unified Messaging Server role, see Unified Messaging.

  • Hub Transport Server   This is the mail routing server that routes mail within the Exchange organization. For more information about the Exchange 2007 Hub Transport Server role, see Hub Transport.

  • Edge Transport Server   This is the mail routing server that typically sits at the perimeter of the topology and routes mail in to and out of the Exchange organization. For more information about the Exchange 2007 Edge Transport Server role, see Edge Transport.