Outlook 2013 cannot connect to Exchange 2013 using MAPI over HTTP when proxy is enabled

Consider the following scenario:

• You are using Microsoft Outlook 2013 version 15.0.4569.1506�or later.
• You are connecting to a Microsoft Exchange Server 2013 Service Pack 1 (SP1) mailbox using the MAPI over HTTP protocol.
• You have a proxy enabled on your Outlook client computer which has your own domain listed as an Exception.

In this scenario, Outlook cannot connect to Exchange. The Status Bar in Outlook displays�DISCONNECTED.

Outlook cannot connect to the Exchange Server using the MAPI over HTTP protocol when a proxy is enabled with your own domain as an Exception.

Microsoft is aware of this issue and may produce a solution in an upcoming release or service pack. Future updates about this solution will be posted to this article.

In order to work around the issue, use one of the following options:

1. Remove your own domain name from the Exceptions in the Proxy settings.
   
   1. In Internet Explorer, click Tools, Internet Options.
   2. On the Connections tab, click LAN Settings.
   3. Click Advanced.
   4. In the Exceptions section, remove your domain.
   5. Click OK on the three open Windows.
2. Disable MAPI over HTTP.
   
   1. Exit Outlook if it is running.
   2. Open Registry Editor.
      
      1. Open the Run box
         
         • Windows 8
           Press the Windows key + R
         • Windows 7 or Windows Vista
           Click Start, and then click Run.
         
         
      2. Type Regedit.exe and click OK.
         
      
      
   3. Locate and select the following key in the registry.
      HKEY_CURRENT_USER\Software\Microsoft\Exchange
   4. After you select the key that was specified in step 3,�click the�Edit menu, point to New, then select DWORD Value.
   5. Type MapiHttpDisabled as the name of the DWORD Value, and then press Enter.
   6. Right-click MapiHttpDisabled, and then click Modify.
   7. In the Value data box, type 1, and then click OK.

For more information about the requirements for MAPI over HTTP connections, go to the following Microsoft TechNet website:
MAPI over HTTP

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