Using Outlook with Exchange Outside the ISU Network

A typical Outlook and Exchange environment assumes all clients are part of a protected network. At Iowa State University, that includes both the ISU campus network and remote Extension offices. Outlook will not communicate with Exchange beyond these network locations (e.g., from home or while traveling) without some additional work. While Outlook Web Access ( can be used in these cases, sometimes the full Outlook 2003 client is desirable. Two additional options are available to securely access Exchange using Outlook.

Option 1: Virtual Private Networking

A Virtual Private Network (VPN) is a secure connection between your computer and ISU. While connected, your computer is logically part of the ISU network and can access all the same resources as if it were physically there. This includes file shares and other services as well as Exchange. Detailed VPN setup instructions are available. Once connected, configure and use Outlook normally.

Options 2: RPC over HTTPS

RPC over HTTPS is a way of securely accessing Exchange through a proxy. Only Exchange communication is proxied; other resources such as file shares will not be available unless using VPN. Complete the following steps to reconfigure Outlook to use RPC over HTTPS.

For Outlook 2007 only:
  1. Select Tools, Account Settings
  2. Highlight '' / 'Exchange', click Change
For Outlook 2003 only:
  1. Select Tools, Email Accounts
  2. Select View or Change existing email accounts, Next
  3. Highlight 'Microsoft Exchange Server', click Change
For both Outlook 2007 and 2003:
  1. Select the More Settings button
  2. Select the Connection tab
  3. Check Connect to my Exchange mailbox using HTTP
  4. Click Exchange Proxy Settings
  5. Enter
  6. Check the appropriate boxes to choose when to use HTTP:
    a. For a system used mostly or entirely off the ISU network without VPN, check both On fast networks… and On slow networks…
    b. For a mobile system that travels to and from the ISU network, select only On slow networks, connect using HTTP first, then connect using TCP/IP
  7. Under Proxy authentication settings select Basic authentication
  8. Select OK twice
  9. Select Next, Finish