They like Outlook because of many reasons and alerts of new mail appearing on the desktop is just one of them. Many users still use Microsoft Outlook for its features.
But when it comes to successful integration of mail service, calendar, peoples all in one place- no one can deny the efficiency of Outlook. Though after the introduction of Mail application on Windows 10, users are more tending to use Mail rather than using Outlook. Since then, the application has changed a lot, became more colorful and flamboyant with regular updates. Microsoft Outlook is a webmail service-based application which is an integral part of Windows MSN services since Windows 2000.