Outlook - Classic & New Object: Outlook - Classic & New Description This document explains the differences between the two available versions of Microsoft Outlook to help you identify which one you are using. Steps Recognize Classic Outlook as the most complete version. It will eventually be replaced but will remain functional until at least 2029. Recognize the New Outlook as the version currently in development. You can use it now, but it does not yet have all the features of Classic Outlook.