Microsoft Exchange Server 2007 has five server roles that you can implement and configure on a server running Microsoft Windows Server 2003. The Client Access Server role is required for mobile messaging deployments and provides access to the following applications and services:

• Microsoft Outlook Web Access
  
• Exchange ActiveSync
  
• Post Office Protocol version 3 (POP3)
  
• Internet Messaging Application Protocol version 4 (IMAP4)
  

Note:
Exchange ActiveSync is enabled when the Client Access Server role is installed.

The Client Access Server role is added by default during a typical Exchange installation. It may also be installed on a separate server by selecting a custom option. The decision to deploy Exchange Server 2007 on a single server or in a distributed-role architecture depends on the messaging needs and requirements of your organization.

Note:

The Client Access Server role should never be installed in the perimeter network unless you are deploying Exchange in a Microsoft Small Business Server deployment. In that configuration, Microsoft recommends that you use a firewall to funnel all Internet traffic that is bound for your Client Access Server. It is also a best practice to run Exchange Best Practice Analyzer before proceeding with your deployment. You can download the Microsoft Exchange Best Practices Analyzer at http://go.microsoft.com/fwlink/?LinkID=87079.

To deploy Microsoft Exchange 2007, see the following technical documentation:

The topics presented in these articles include planning and architecture for simple, standard, large, and complex Exchange deployments. The topologies in Network Architecture Alternatives enable both a typical (single server) and a custom (multiple server) installation.

Note:
This document describes procedures and guidelines for deploying Windows Mobile 6 with Exchange Server 2007. Exchange Server 2007 roles other than the Client Access Server or Mailbox Server roles are not core components of a mobile messaging system, and are not documented here.