Microsoft won't let you block lock new Outlook on Windows 10 (auto-install) but you can remove it via PowerShell.

Microsoft will force install the new Outlook email client on Windows 10 systems starting with next month's security update.

Designed to replace the current Mail and Calendar apps, the new Outlook can only be removed after it's been installed.

Microsoft decided to force install the new Outlook on Windows 10 starting with the new updates of the OS. You can quickly uninstall it after.

Microsoft announced last year that it would be retiring the Windows Mail & Calendar apps in favor of the new Outlook at the end of 2024. As of January 1, these apps are no longer functional and will refuse to send or receive any more emails.