Does anyone know if Zimbra desktop is really a stand alone app. It appears that Zimbra will not even start up if it does not see a network connection. Also, it appears that there is no real way to close down the application and end all of its services to free up resources.

The main reason I am looking for a desktop application is to review and work on email offline and then send. If it is not an offline capable application why wouldn't I simply use the web based email clients?