Folder Levels is a Thunderbird addon that lets you rank your email folders by how much you care about them, and hide the ones you don’t need right now.
Learn more about Folder Levels at http://jeremyiverson.github.com/folderlevels/.
This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.