Last reviewed on March 12, 2015   —  23 Comments

Applies to Microsoft Outlook 2013 and Outlook 2010

When you install Outlook 2010 or Outlook 2013 and try to send mail using the File, Send by email command in other applications, Outlook may not be recognized as the default mail client.

The causes include:
1. You are using Outlook 64-bit and 32-bit programs can't "see" 64-bit programs.
2. You are using Home and Business 2010 "Click to Run" (C2R) suite, which is installed in a virtual drive. Other applications can't see Outlook 2010 C2R. Note: This does not apply to Outlook 2013. All Office 2013 suites are click-to-run; most applications will not have problems due to this.
3. Installing the application AFTER installing Office. The fix: repair Office.

Verify Outlook is set as default mail client

To verify Outlook is indeed set as your default email client:

Set Outlook as your default email client

  1. Open Control Panel and search for Default Programs.
  2. Select Set Default Programs link.
  3. Choose Microsoft Outlook from the list of programs.
    Click "Set this program as default".

Repair Office installation

If the affected program was installed after Office, try repairing the Office installation.

  1. Open Control panel, Program and Features
  2. Find and select your Office or Outlook installation
  3. Click Change
  4. Select Quick Repair then click the Repair button. (In older versions of Office, the option is called Repair.)
    repair office

Using Outlook 64-bit with 32-bit Applications

Using 64-bit Office is not recommended unless you need large (2GB) file support in Excel or Access. There is no benefit in using Office 64 bit for "normal" users. Also, you cannot mix-and-match Office 'bitness' - you need to use all 64-bit or all 32-bit Office applications. See 64-bit editions of Office 2010 for Microsoft's recommendations.

If you are using Office 2013 64 bit, check this registry key and create it if it does not exist.

String: Bitness
Value: x64

If you don't want to edit the registry yourself, you can download and run this registry file:
Outlook 2013.

Outlook 2010 Click to Run

If you are using Outlook 2010 Home and Business C2R, you should uninstall it then log into the download site and download the MSI. This will install the traditional Office suite, which is recognized by other applications.

Note: All Office 2013 suites sold "retail" are "click to run". It was designed to work like the traditional MSI installation. Only certain volume licenses include the MSI installation.

If you choose to use the following registry hack, you do so at your own risk - it puts Outlook into an unsupported mode. If you have problems with Outlook, you need to remove these keys before troubleshooting. Our recommendation is to use 32-bit Office.

In the Start menu's Search field, type regedit then press Enter. (You'll probably need to ok a security dialog.)

In the Registry editor, browse to
Right click on the Mail key and Export a copy for backup.

Right-click on Mail again and create a new key called Outlook64Bridge

Next, right-click on Outlook64Bridge and create a key under it called DLLPath. Right-click again and create a key called DLLPathEx.

Locate the 32 bit version of the file MAPI32.dll on your computer and enter the complete path name in each DLLPath key (replacing "something\something\...." with the correct path on your computer):



(On my computer, a mapi32.dll is at C:\Windows\winsxs\x86_microsoft-windows-mapi_31bf3856ad364e35_6.1.7601.17514_none_ad54ab3a7801c830)

Next, change the default client to Outlook64Bridge:


Outlook64Birdge Registry key


  1. John Yoder says

    Your third suggestion in your list is to chose Outlook from the list of programs, but I don't see Outlook in the list, so I can't chose it as the default.

    • Dave Walkiden says

      I have been chasing this problem for about a week, trying all the suggestions here but none worked. in the end it was an add-in in outlook created by Adobe Acrobat Pro. I just un-ticked it in the add-ins options and it worked first time. Hope it helps someone else. Dave

  2. Delaine says

    Hi Diane,
    I need to get help using Outlook as my primary contact manager and learn to use all of the features of the product for managing contacts, categories, groups, folders, reminders, calls, etc. I am an advanced user of Outlook, but there are things I don't understand about the contacts portion. Do you offer paid training programs via the internet, phone, webinars, etc? Or one on one packages?

    • Diane Poremsky says

      I do offer one-on-one assistance using GoToMeeting. You can contact me at diane [at] for more information.

    • Diane Poremsky says

      Are you using a category view? Try one of the icon views or type default into the Search Control Panel box.

  3. Eileen Shukaitis says

    I keep getting the error message. I have checked to make sure I have 32-bit and Outlook is set as my default. Any other suggestions?

    • Diane Poremsky says

      What are you trying to do when the error comes up? Are you using Outlook 2013? Many applications won't work with it without an upgrade.

  4. Phil says

    Hi Eileen,

    I have followed your instructions but I find that the ...\Mail default key, that we change to Outlook64Bridge, keeps on getting changed back to Microsoft Outlook.

    Can you advise please?


  5. John Duffy says

    Hi Diane,
    I'm implementing a new CRM and i cannot get the send email working at all. I have followed your instructions to the letter but it still fails with the default mail error.
    I tried even using 64 bit IE but the thing hangs now.
    Can you help please?
    John Duffy

    • Diane Poremsky says

      It's possible the CRM wasn't designed to work with the newer Outlook versions. Are you using 32 or 64-bit Office? It may work with 32-bit.

  6. Michael says

    Is there a known fix for Outlook 2013 64 bit and 32 bit apps, Outlook64Bridge dos not seem to work

    • Diane Poremsky says

      No, sorry, there are no fixes, except switching to 32bit Office or maybe upgrading the application, if a newer version was designed to work with 64bit outlook 2013.

  7. Math says

    I'm using Office 2010 64-bit and Windows 7 64-bit and folowwed the procedure and it does not work. How to I have Windows point to Outlook64Bridge as the default key?

  8. jack says

    i dont have the m/s outlook there is no option to set as i have and running in tandem..with as my default...which updates (eventually) my email..

  9. Bigwil806 says

    Diane, I'm trying to run CalCheck_x86 on my Outlook 2010 32bit program but I keep getting a message that Outlook is not the default mail client. I've verified that it is indeed the default mail client. Why can't I get CalCheck to run?

    • Diane Poremsky says

      You are using an Exchange mailbox? It won't work with other calendars. It should throw up a different error if that is the problem though.

      Do you have multiple profiles? If so, set Outlook to always use a specific profile.

  10. Andrew says

    That doesn't seem to work... I had to recently rebuild the computer after a meltdown in China and I just can't seem to get it to work again properly. Also now on Windows 10... I used an App previously and it fixed it...

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