If your Ribbon is in Simplified mode, (One line of icons), click "Ribbon Display Options". This is on the far right, denoted by a small dropdown arrow.

Microsoft Outlook is an email application. In addition to email client services, Outlook includes features for managing calendars, tasks, contacts, and notes, helping users stay organized and productive. Learn how to manage your account, set up your Outlook email signature, specify out of office hours, and much more.