How do I configure Outlook 2003 to use RPC over HTTP?

The following article explains how to configure Outlook 2003 to use RPC over HTTP. Users that attempt to use Outlook 2003 to connect to an exchange server may find their connection being blocked. One cause of the blocked connection may be a firewall. To get around the block, Outlook 2003 can be configured to use a protocol called RPC. RPC allows Outlook 2003 to connect to an exchange server over HTTP. Firewalls typically do not block HTTP, as it is used for normal Web browsing.

Please Note: This solution will only work using Outlook 2003 on a Windows XP machine. If the Windows XP machine is running Service Pack 1, the following hotfix located here will need to be installed. If the Windows XP machine is running Service Pack 2, the hotfix does not need to be installed.

To configure Outlook 2003 to use RPC, please follow these steps:

1. Click the Start button on your machine and select Control Panel.
2. Right click on Mail and select Properties.
3. Click Add.
4. Enter a Profile Name for the profile. This can be any name you wish.
5. Select Add a new e-mail account and click Next.
6. Select Microsoft Exchange Server and click Next.
7. Enter the necessary information:
   • Microsoft Exchange Server: enter the fully qualified domain name (FQDN) of the exchange server
   • User Name: enter the user account name configure on the exchange server
   
8. Check Use local copy of Mailbox
9. Click More Settings
10. Click the Connection tab.
11. Select Connect using my Local Area Network.
12. Check Connect to my Exchange mailbox using HTTP.
13. Click Exchange Proxy Settings.
14. Enter the fully qualified domain name (FQDN) as the URL to connect to the proxy server for Exchange.
15. Check Mutually authenticate the session when connecting with SSL.
16. Enter msstd:FQDN as the Principal name for proxy server.
17. Check Connect using HTTP first, then connect using my Local Area Network (LAN).
18. From the drop down, select Basic Authentication.
19. Click Ok twice and then click Next.
20. Click Finish.