The New mail folder has its own toolbar icon to reflect its importance, and it is the folder you'll probably spend a lot of your Pegasus Mail time in.
Pegasus Mail's "New mail" Folder Explained
The New mail folder is where all new mail (from all POP accounts) shows up first. Even if you use filters to sort incoming messages automatically, they are originally delivered to the new mail folder and only filtered after you open that folder.
