Outlook 2013 may not connect using MAPI over HTTPs as expected

Article ID: 2937684 - View products that this article applies to.
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Consider the following scenario.
  • You are using Microsoft Outlook 2013 Service Pack 1 (SP1).
  • You are connected to a Microsoft Exchange Server 2013 Service Pack 1 (SP1) mailbox.
  • The Exchange 2013 mailbox and Client Access (CAS) servers that you are connecting to all have SP1 installed.
  • The necessary server settings to establish MapiHttp connections are correctly configured.
In the above scenario, the Protocol column in the Outlook Connection Status dialog shows Outlook 2013 is connected to the Exchange server using a connection mechanism other than MAPI/HTTP. For example, the following figure shows a connection using RPC/HTTP.
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Note MAPI/HTTP connections are designated in the Protocol column using the string HTTP.


This problem can occur if the MapiHttp feature is disabled on the Outlook client using the following registry value:
Key: HKEY_CURRENT_USER\Software\Microsoft\Exchange
DWORD: MapiHttpDisabled
Value: 1


To resolve this problem, change the value of MapiHttpDisabled to 0 (zero) or delete the MapiHttpDisabled DWORD value. This registry data is intended for testing purposes only.
  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

        On the Start menu click Run.
    2. Type Regedit.exe and click OK.
  3. Locate and select the following key in the registry.

  4. Right-click MapiHttpDisabled and then click Modify.
  5. Change the Value data to 0 and then click OK.
  6. Close Registry Editor.
  7. Start Outlook.

More information

For more information about the requirements for MAPI over HTTP connections, visit the following Microsoft TechNet website:
Note This is a "FAST PUBLISH" article created directly from within the Microsoft support organization. The information contained herein is provided as-is in response to emerging issues. As a result of the speed in making it available, the materials may include typographical errors and may be revised at any time without notice. See Terms of Use for other considerations.


Article ID: 2937684 - Last Review: February 28, 2014 - Revision: 3.0
Applies to
  • Microsoft Exchange Server 2013 Service Pack 1

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