Using New Outlook on Windows for professional communication and productivity
Hi I also found another way to stop outlook from auto installing, after I recently ran windows update, found as soon as I opened mail it took me to outlook, immediately closed and uninstalled outlook, I opened mail again and that damn outlook reinstalled, so every time outlook uninstalled it kept reinstalling, so I deleted Outlook update in the registry, now have mail back permanently, with no pesky "try Outlook" pop up in mail, but do have the try Outlook button still there, strange thing as well I ran windows store update and my mail app had an update so updated, so MS must be still supporting Mail for now.
My fix: [-HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsUpdate\Orchestrator\UScheduler_Oobe\OutlookUpdate]
I went to this location and deleted the OutlookUpdate file, I checked my mail app after pc reboot and all ok up to press, few days now now issues.