Client Access

Microsoft Exchange Server 2007 will reach end of support on April 11, 2017. To stay supported, you will need to upgrade. For more information, see Resources to help you upgrade your Office 2007 servers and clients.


Applies to: Exchange Server 2007, Exchange Server 2007 SP1, Exchange Server 2007 SP2, Exchange Server 2007 SP3

In Microsoft Exchange Server 2007, there are five server roles that you can install and then configure on a computer that is running Windows Server 2003. This topic provides an overview of the Client Access server role. The Client Access server role supports the Microsoft Office Outlook Web Access and Microsoft Exchange ActiveSync client applications, Outlook Anywhere, Microsoft Entourage 2004 and Entourage 2008 for Mac, and the Post Office Protocol version 3 (POP3) and Internet Message Access Protocol version 4rev1 (IMAP4) protocols. The Client Access server role also provides access to free/busy data by using the Availability service and enables clients that are running Microsoft Office Outlook 2007 and certain mobile operating systems to download automatic configuration settings from the Autodiscover service.

The Client Access server role accepts connections to your Exchange 2007 server from many different clients. Software clients such as Outlook and Eudora use POP3 or IMAP4 connections to communicate with the Exchange server. Hardware clients, such as mobile devices, use ActiveSync, POP3, or IMAP4 to communicate with the Exchange server. You must install the Client Access server role in every Exchange organization.

For more information about the new client features in Exchange 2007, see New Client Functionality.

For more information about Entourage 2008 for Mac, see the Microsoft Office 2008 for Mac Administrator’s Guide.

Outlook Web Access

Outlook Web Access in Exchange 2007 lets you access your e-mail from any Web browser. Outlook Web Access has been redesigned in Exchange 2007 to enhance the user experience and productivity in many ways. New features, such as smart meeting booking, Microsoft Windows SharePoint Services and Windows file share integration, and improvements in reminders and the address book give you a rich user experience from any computer that has a Web browser. There are two versions of Outlook Web Access included in Exchange 2007: the full-featured Outlook Web Access Premium client and the new Outlook Web Access Light client. Outlook Web Access Light is designed to optimize your Outlook Web Access experience for mobile devices, slower connections, and browsers other than Internet Explorer.

For more information about Outlook Web Access, see the following topics:

Exchange ActiveSync

Exchange ActiveSync lets you synchronize data between your mobile device and Exchange 2007. You can synchronize e-mail, contacts, calendar information, and tasks. Devices that run Windows Mobile software, including Windows Mobile powered Pocket PC 2002, Windows Mobile powered Pocket PC 2003, and Windows Mobile 5.0, are all supported.

If you use a device that has Windows Mobile 5.0 and the Messaging Security and Feature Pack (MSFP) installed, your mobile device will support Direct Push. Direct Push is a technology that is built into Exchange ActiveSync that keeps a mobile device continuously synchronized with an Exchange mailbox.

For more information about Exchange ActiveSync, see the following topics:


In addition to supporting MAPI and HTTP clients, Exchange 2007 also supports POP3 and IMAP4 clients. By default, POP3 and IMAP4 are installed but the services are disabled when you install the Client Access server role.

For more information about POP3 and IMAP4, see the following topics:

The Availability Service

The Exchange 2007 Availability service improves free/busy data access for information workers by providing secure, consistent, and up-to-date free/busy data to computers that are running Outlook 2007. Outlook 2007 uses the Autodiscover service to obtain the URL of the Availability service. The Autodiscover service resembles the Domain Name System (DNS) Web service for Outlook 2007. Essentially, the Autodiscover service helps Outlook 2007 locate various Web services, such as the Microsoft Exchange Unified Messaging, Offline Address Book, and Availability services.

For more information about the Availability service, see the following topics:

The Autodiscover Service

The Autodiscover service enables Outlook clients and some mobile devices to receive their necessary profile settings directly from the Exchange server by using the client's domain credentials. These settings automatically update the client with the information that is needed to create the user's profile.

For more information about the Autodiscover service, see the following topics.