by Daniel Petri - January 7, 2009

http://www.petri.co.il/configure_outlook_2003_to_use_rpc_over_http.htm

RPC over HTTP/S is a cool method for connecting your Outlook 2003 client to the corporate Exchange Server 2003 from the Internet or WAN, without the need to establish a VPN session to the corporate LAN and/or needing to open many ports on your corporate firewall. The only ports you'll need to open on your firewall are TCP 80 and, if using SSL, TCP 443.

 To set up a new Outlook profile that uses RPC over HTTP/S to connect toan Exchange Server.

1. Open Control Panel and run the Mail applet.

2. In the Mail applet click on Show Profiles.

1. In the Mail window click on Add.

1. In the New Profile window type a descriptive name and click Ok.

1. In the E-Mail Accounts window select Add a new e-mail account and click Next.

1. In the E-Mail Accounts window, select Microsoft Exchange Server and click Next.

1. In the E-Mail Accounts window, under the Microsoft Exchange Server box, type the Internal NetBIOS name of the Exchange server. Next, in the User Name box type the logon name of the test user account, the one you'll be connecting with.

Note: Although pressing the Check Name button will work in the LAN environment, it will NOT work on the WAN, so basically there is no point in pressing it. Next click More Settings.

Note: In this test scenario I recommend NOT to use Cached Mode. We're working on the LAN, our network connection is steady and fast, and this is only a test account. However, in WAN scenarios where a user needs to connect to his or her mailbox from their portable computer - you should use Cached Mode.

1. In the Microsoft Exchange Server window, go to the Connection tab. Notice that you should have a section called "Exchange over the Internet" at the bottom of the tab. If this section does not appear, it means that you might not have met the requirements for setting up an RPC over HTTP/S connection. See the "Client Requirements" section on the Configure RPC over HTTP/S on a Single Server page.

In the Exchange over the Internet section click to select the Connect to my Exchange mailbox using HTTP, and then click on the Exchange Proxy Settings button.

1. In the Exchange Proxy Settings tab in the Connection Settings box, type the FQDN (Fully Qualified Domain Name) of the Exchange server.

Note: For LAN testing you CAN type the Internal FQDN of the server. For WAN connections you MUST type the External FQDN of the server. See Testing RPC over HTTP/S Connection for more on this issue. The external FQDN of the server is the fully qualified domain name that is used by the Outlook clients to connect to the server from outside the LAN, and must be resolved to the IP address of the server, or in most cases, resolved to the IP address of your Firewall (or NAT device) that is configured to transfer the requests to the internal IP address of the Exchange 2003 server.