Highlights of the beta 4 release include a feature to delete mail folders, support for mail signatures, tooltips for email addresses in message headers, and the ability to drag-and-drop mail folders to other mail folders. America Online's AOL Desktop for Mac beta update allows users to print mail, ensures that mail is compatible with Mac OS X 10.5 Leopard, and enhances the dial-up experience. The latest revision also adds support for groups as well as host synch to the address book, and adds AIM Chat (public beta) to the application toolbar.