Weclome to the forums.
Zimbra isn't a web-app it's a Collaboration Suite a descriptiosn of the Features can be found
here (if you haven't seen it already). The likelihood is that you would have difficulty installing it on a godaddy hosted serv as they usually have all sorts of service and control panels installed, not impossible but you'd be better with just a bare operating system host (we recommend that Zimbra is the only application running on the server). Perhaps if you posted some details about what you're trying to do someone may be able to offer more detailed advice.