Alphabetic Sorting Is Automatic

Alphabetic Sorting is Automatic for Alphabetic Folders
You don't have to do anything in order to have alphabetic folders sorted. Folders' contents get sorted regardless of whether the 'Sort Preview' button was pressed or not on a particular folder.

What does 'Sort Preview' do?
Two things:
• It provides the user with a preview of the true final sort order of items on the web, after items are appended, deleted, etc. in the 'Folder Contents' list. That's a preview only; with or without it, the folder's content gets sorted anyway.
• Restores dragging to position in manual sorting folders, after some temporary sort order has been employed. For instance, you've been dragging items to position in a folder that's set for manual sorting. At some point, you need to see the items sorted by their filenames, and press the 'Filename' column header. Now, in order to be able to drag items to position again, first press 'Sort Preview'; this restores the order you've been working on.