The quick access bar is an important part of your Outlook interface. It’s an easy way for you to use along with Outlook features: Mail, Calendar tool, People, and Outlook Tasks.
It’s located at the bottom of the Outlook window, the quick access bar shows button names (left image) or icons (right image) associated with feature names.
The icons appear on the quick access bar
Easily control which buttons (or icons) appear on the quick access bar and what order they appear.