In the forums, we have talked a lot about webmail clients like Squirrelmail, Horde, Uebimiau and RoundCube. There is also another nice, well designed and easy to use webmail client: IlohaMail, my personal favorite, which deserves more attention. It provides similar functions as Horde but is not so difficult to setup. In my "mini how to" i explain how you can setup IlohaMail on your perfect server with ISPConfig. Link to my how is now located here: http://www.howtoforge.com/ilohamail_ispconfig (URL changed after Falko's post on Howtoforge). Enjoy IlohaMail!