Postbox goes above and beyond in terms of helping users catalog their email. After setting up the application, users can click on the "Images" tab to see a thumbnail gallery of every picture contained within their various messages. The "Compose" sidebar is another fine feature, and it gives users the availability to find attachments, images, and links directly within a new message window. This version of Postbox is compatible with computers running Mac OS X 10.4 and newer.