I know, I know. Mutt, Elm, Pine, and Emacs all provide millions of happy users with all the email they can read. But to grow the community even larger and become a recognized player on the desktop, Linux must deliver an email client that recent converts from the dark side can easily navigate and use. If there is a way to automate mail gathering, I haven't found it yet. But there is a nice icon to click when you want to get new mail.
Evolution provides for folders and nested folders.
You can quickly and easily set up filters to drop the incoming mail wherever you like. In my experience, the filters do not yet work all the time. I suspect that closer examination will show that the filtering problem stems from my configuration, not from Evolution. Evolution handles that just fine, and since I started running it, my spam has been a lot easier to read. I subscribe to one mailing list devoted to photographs of donkeys and mules.