I found this script on a different thread. You have to change the profile username but the script then executes correctly. You'll have to find that by opening File Explorer and browsing to your user folders. Tap the Windows button & R and type %userprofile% in the box and press enter to find it. It's usually the first five digits of whatever name you used when you created your profile at setup.

So, right click on the Start button, choose Terminal (Admin), paste this all in but make sure you change the INSERTUSERNAME area to your username. Then press enter. Hopefully it sticks but I can't be sure of that yet. It reinstalled itself twice this morning so I guess I'll see tomorrow or after I restart my computer again today.

$folderPath = "C:\Users*INSERTUSERNAME*\AppData\Local\Packages\microsoft.windowscommunicationsapps_8wekyb3d8bbwe\LocalState\Migration"

$acl = Get-Acl -Path $folderPath

Find the deny write rule applied earlier

$denyWriteRule = $acl.Access | Where-Object {

$\_.IdentityReference -eq "Everyone" -and   

$\_.FileSystemRights -eq "Write" -and   

$\_.AccessControlType -eq "Deny"   

}

if ($denyWriteRule) {

$acl.RemoveAccessRule($denyWriteRule)   

Set-Acl -Path $folderPath -AclObject $acl   

Write-Host "Write access restored for $folderPath"   

} else {

Write-Host "No deny write access rule found for $folderPath"   

}

It's obvious Microsoft Email developers have made up their minds to force feed the New Outlook Mail app to it's users because its a revenue generated opportunity that comes with the app. It's all about advertisements and advertisements spells money no matter how much people like myself whined about how much they hate it it's not going anywhere no time soon. Because remember they are reading the comments too and see the dislike of their baby and the harsh reality is they do not care. So I think anyone that don't like the New Outlook mail app should buckle down and learn how to use it or do what I've done repeatedly. I keep uninstalling it and use the Old Mail app while I'm using it and repeat the process each time I use it because you can use the Old Mail app until you turn off your computer and restart it and it will continue to reinstall the New Outlook Mailing app and so far that's the only work around that I know of and soon the developers are going to find a way to get rid of that little infraction😒.

No you shouldn't have to, but sometimes that is the only way to stop Mr Softy from running roughshod. Only other option is find something else. That is next on my list when the time comes. I am looking at Thunderbird to replace my full purchased desktop Outlook that i have been using forever before they started trying to drive this stripped down piece of **** web-ware down our throats instead of a local installed client.

Thanks Sean,
But should we really have to alter the registry for them to stop doing this. It has now removed my mail from the taskbar, replaced it with a pinned new outlook, and uninstalled mail & calendars from my computer. Probably because I uninstalled new outlook 20 times!