How to redirect an HTTP connection to HTTPS for Outlook Web Access clients (839357)


The information in this article applies to:

  • Microsoft Exchange Server 2003 Enterprise Edition
  • Microsoft Exchange Server 2003 Standard Edition
  • Microsoft Exchange 2000 Enterprise Server
  • Microsoft Exchange 2000 Server
  • Microsoft Exchange Server 5.5

INTRODUCTION

This article describes how to automatically redirect an HTTP connection to an HTTPS connection in the Microsoft Internet Information Services console (IIS) for Microsoft Outlook Web Access users.

We recommend that you require a Secure Sockets Layer (SSL) connection for your Outlook Web Access users. An SSL connection encrypts the information that is sent to or received from the Microsoft Exchange Server computer. However, when you configure IIS to require SSL for all incoming Outlook Web Access requests, Outlook Web Access users who try to connect by using HTTP receive the following error message:
HTTP 403.4 - Forbidden:
SSL required
Internet Information Services
After the Outlook Web Access user receives the error message, the user must manually type https:// at the start of the URL to connect to the Exchange Server computer. You may want to configure IIS to automatically redirect the Outlook Web Access user's HTTP request to HTTPS to minimize user interaction and to make sure that all incoming requests are enabled for SSL.

MORE INFORMATION

To configure IIS to automatically redirect HTTP requests as HTTPS requests, follow these steps.

Important If the following conditions are true, you must mount and start the mailbox store before you can successfully complete these steps:
  • Microsoft Exchange 2000 Server or Microsoft Exchange Server 2003 is installed on a front-end server.
  • The mailbox store has been dismounted.
Note Follow these steps on an Exchange front-end server that communicates with a clustered Exchange back-end server.
  1. Create an Active Server Pages (ASP) Web page that contains the following code: 
     <%

If Request.ServerVariables("HTTPS")  = "off" Then
						Response.Redirect "https://" & Request.ServerVariables("HTTP_HOST") & "/Exchange"
End If 

	%>
  2. Name the Web page "Owahttps.asp".
  3. In Windows Explorer, create the Inetpub\Wwwroot\CustomErrors folder, and then save the Owahttps.asp Web page file to that folder.
  4. Start the IIS console.
    • In Windows NT Server 4.0 (IIS 4.0)

      Note Follow these steps if you are running Microsoft Exchange Server 5.5 Outlook Web Access on Windows NT 4.0 Server with the Windows NT 4.0 Option Pack. If you have an Exchange Server 5.5 mailbox server, and if the Outlook Web Access component is installed separately on a dedicated Web server, follow these steps on the Web server only.
      1. Click Start, point to Programs, point to Windows NT 4.0 Option Pack, point to Microsoft Internet Information Services, and then click Internet Services Manager.
      2. Expand Internet Information Server, expand Computer Name, and then expand the Web site that the Outlook Web Access users use to access their Exchange server. By default, this Web site will be the default Web site.
      3. Go to step 5.
    • In Windows 2000 Server (IIS 5.0)

      Note Follow these steps if you are running Exchange Server 5.5, Exchange 2000, or Exchange 2003 Outlook Web Access on Windows 2000 Server.
      1. Click Start, point to Programs, point to Administrative Tools, and then click Internet Services Manager.
      2. Double-click Computer Name to expand the computer object.
      3. Expand the Web site that the Outlook Web Access users use to access their Exchange server. By default, this Web site will be the default Web site.
      4. Go to step 5.
    • In Windows Server 2003 (IIS 6.0)

      Note Follow these steps if you are running Exchange 2003 Outlook Web Access on Windows Server 2003.
      1. Click Start, point to All Programs, point to Administrative Tools, and then click Internet Information Services (IIS) Manager.
      2. Expand Computer Name, and then expand Web Sites.
      3. Expand the Web site that your Outlook Web Access users use to access their Exchange server. By default, this Web site will be the default Web site.
      4. Go to step 5.
  5. Right-click the CustomErrors folder, and then click Properties.
  6. Under the Application settings section, click Create.

    Make sure that CustomErrors is displayed in the Application name box.

    Note For Exchange 2003 running on IIS 6.0, click ExchangeApplicationPool in the Application Pool list.
  7. Click the Documents tab, and then add the Owahttps.asp file to the Enable default content page. Move the Owahttps.asp file to the top of the list.
  8. Click the Directory Security tab, and then click Edit under Authentication and access control.
  9. Click to select Enable anonymous access, and then click OK.
  10. Under Secure communications, click Edit.
  11. Click to clear the Require secure channel (SSL) check box, and then click OK two times.
  12. Right-click the Exchange virtual directory, and then click Properties.
  13. Click the Custom Errors tab, and then double-click 403.4.
  14. In the Message Type list, click URL.
  15. In the URL box, type /CustomErrors/Owahttps.asp, and then click OK.
  16. Click the Directory Security tab.
  17. Under Secure Communications, click Edit.
  18. Click to select the Require secure channel (SSL) check box.

    Note If you want to require 128-bit encryption, click to select the Require 128-bit encryption check box.
  19. Click OK two times.

    Note The Exchange virtual directory and the Public virtual directory are the only virtual directories that you have to configure to require SSL. If you have other virtual directories for which you want to require SSL, enable SSL on each virtual directory individually.
After you follow these steps, visit the following Web site:

http://<server_name>/exchange

In this address, server_name is the name of the Microsoft Internet Information Service (IIS) server.

You should be automatically redirected to https://<server_name>/exchange and to the Logon.asp page.
Modification Type:MajorLast Reviewed:3/17/2006
Keywords:kbinfo KB839357 kbAudITPRO
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