Client-side:

* Outlook 2003, Windows XP with Service Pack 1 + Q331320

Server-side:

* Exchange 2003 on Windows 2003 for FE (if FE is deployed)

* Exchange 2003 on Windows 2003 for BE

* Exchange 2003 on Windows 2003 for Public Folders

* Exchange 2003 on Windows 2003 for System Folders

* Windows 2003 for Global Catalog server

When used with the Microsoft Windows Server 2003 RPC Proxy Service and Exchange 2003, Outlook 2003 clients can connect simply using HTTP or HTTPS, thereby reducing the need for virtual private networks (VPNs) or dial-up remote access. If remote users only need to gain access to corporate messaging information, your IT department may not need to deploy VPN infrastructure. VPN-less access reduces costs and provides for increased security by ensuring that remote Outlook users don’t need access to the entire network.