This is driving me crazy...
Hello everyone!
I am trying to change some M365 desktop apps preferences via Regedit and I am hitting a brick wall of inconsistency.
For example:
I want to change ReadingPane preferences in Outlook 365 desktop app.
At first I added:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\Preferences
DWORD: PreviewDontMarkUntilChange and PreviewMarkMessage both valued: 0
At first it seemed to work with both options greyed out in the Outlook Options GUI.
Checking after a reboot the options where again available.
So I added:
HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\Office\16.0\Outlook\Preferences
DWORD: PreviewDontMarkUntilChange and PreviewMarkMessage both valued: 0
Does not seem to work consistently.
Attempted with both registry locations, attempted with either one on its own. There are some magical times when it works, and some others where it doesn't...
I am trying to automate some preferences for a M365 Business Premium Tenant...and I am hitting a brick wall.
Any help is welcome.
Thank you for your time.

