Users can't connect to Outlook Web App by using the HTTP protocol in Exchange Server 2010

Original KB number:   2748253


After you apply Exchange Server 2010 Service Pack 2 (SP2), users can't connect to Outlook Web App by using the HTTP protocol. This problem occurs even if you disable the Require secure channel (SSL) option in the Outlook Web App virtual directory.


This problem occurs because Exchange Server 2010 SP2 uses the HTTPS protocol to connect to Outlook Web App.


To work around this problem, follow these steps:

  1. In the Client Access Server (CAS) server that hosts the Outlook Web App, open the Web.config file by using Notepad. By default, the Web.config file is installed in the following location:
    C:\Program files\Microsoft\Exchange Server\V14\ClientAccess\OWA

  2. Locate the following code:

    <httpCookieshttpOnlyCookies="false" requireSSL="true" domain="" />
  3. Change the value of the requireSSL attribute to false, as in the following example:

    <httpCookieshttpOnlyCookies="false" requireSSL="false" domain="" />
  4. Make sure that the new value takes effect. To do this, run the iisreset /noforce command to restart Internet Information Services (IIS).