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

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

Microsoft will automatically install its new Outlook client on Windows 10 PCs with next month’s Patch Tuesday update.

Microsoft will start automatically installing its new Outlook email app on Windows 10 devices. It's already pre-installed on most Windows 11 PCs and rolled out to some existing Windows 11 systems.

The good news is that the February update which brings the new Outlook doesn't strip out the old version of the app, so you can still use that.