Change Message Sorting

Method #1: At the top of your email inbox, click the drop-down menu next to By Date. You will see a list of different options.
Note: It may not always be By Date if it has already been changed

Method #2: At the top of your Outlook window, click the View tab.
Within the Arrangement section, you will find the same options as before.

Advanced Options via Method #2: Click the drop-down arrow in the bottom-right of the Arrangement section and select View Settings.
You’ll see a complete list of options on changing how you want Outlook to be sorted.