Why are my folders not displaying in alphabetical order in Outlook?

Outlook 2013 allows you to have folders in any order you choose - you can re-arrange them however you see fit. By default, they are not sorted in alphabetical order but you can resort them alphabetically if you choose. To do so, right click on your account on the left hand side of your Outlook screen, and select "Sort Subfolders A to Z" 

 

 

If you always want your folders to be displayed alphabetically, you can click on the Folder tab in the ribbon, and turn on "Show All Folders A to Z"