Windows 10: Outlook Office 365 errors "NOT DEFAULT MAIL CLIENT" even after verifying that IT IS

Thanks for any and all assistance! Been struggling with this for months! I need to save emails .msg on our server here at work - and ALWAYS get these messages: pictures below


"Either there is no default mail client of the current mail client cannot fulfill the messaging request. Please run Microsoft Outlook and set it as the default mail client" when trying to open a .msg on our server OR on my local machine


or when trying to copy to my desktop or to server: "The name XXXXXXXXXXX.msg is not valid."


I have repaired via Microsoft Office 365 2x now, have verified that Default Settings are indeed OUTLOOK have included pictures. Not sure if something needs done w/ registry? Cannot find anything online regarding my EXACT registry - so I'm apprehensive to change/modify.


I've uninstalled, rebooted, and reinstalled several times over the past few months also. Outlook app is also set for default for mail.

:)

 

Problem with registry setting default e-mail client

I have this issue as well. I am using Office 2010 Home and Business and Outlook 2010 is my mail client. This is a relatively new pc and has Office 365 (2016) installed as well. After a recent Windows Update, my default mail client changed to Outlook 2016
-- one of my apps that sends mail stopped working, mail profile missing error). When I try to set my default mail client via the UI, only Outlook 2016 is showing; I can't select Outlook 2010.

I uninstalled Office 365 but Outlook 2010 still does not show up in the UI as a default program. Now I need to find out how to change this in the registry.

The OS is Windows 10 Home

 

Cannot set Outlook '13 as default mail client in Win10: "Either there is no default mail client or..."

Very aggravating issue on my work machine (Dell Optiplex 5050 - Windows 10 Enterprise x64, build 1803 - Spring Creators Update).

Every time I click as .MSG file I get this error:

Either there is no default mail client or the current mail client cannot fulfill the messaging request. Please run Microsoft Outlook and set it as the default mail client.

Outlook already is the default email program. Any ideas how to fix this? If it matters, our email server is Exchange 2007.

UPDATE: I have now tried a repair install of Office Pro '13 and deleting this registry key: HKEY_LOCAL_MACHINE\Software\Clients\Mail\Microsoft Outlook (via MS instructions, albeit very old ones: https://support.microsoft.com/en-us...t-mail-client-or-the-current-mail-client-cann). Neither made a difference.

 

Cannot set Outlook '13 as default mail client in Win10: "Either there is no default mail client or..."

Backup these registry keys with an export first, and then any keys labeled "Microsoft Windows MAPI Preview Handler" delete all or any that may exist in your environment. After this you should reboot the machine immediately before testing just to be thorough.

Further Resources

• Either there is no default mail client or the current mail client cannot fulfil the messaging request. Please run outlook and set it as the default mail client
  
• "This file cannot be previewed because there is no previewer installed for it" error ~