I have a client who can’t open .MSG files with a brand-new Office 10 Pro system, and gets the following error when he tries (using Outlook 2016, installed from Office 365):
Either there is no default mail client or the current mail client cannot fulfill the messaging request.
You might think “aha, I just need to go into the control panel and fix either file associations with .msg files, or perhaps MAPI settings.” You would be wrong. Nope, you’re gonna have to delete a registry key, because of course you are. You’re using Windows!
Open this registry address in regedit:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\PreviewHandlersÂ
And delete the key with Data value of “Microsoft Windows MAPI Preview Handler”.
Poof. That’s it. No more errors, stuff opens as it should. Yay.
https://jrs-s.net/2019/12/16/fixing-outlook-2016-either-there-is-no-default-mail-client/
Thank you so much for the clear and excellent solution to one of the most annoying glitches for which I could find no solution. It even took me months to come across yours!
Same issue (and fix) came up for me in O365 v2019. Thanks.