I use the webmail interface to Zimbra quite often and find that the various toolbars (navigation, location, links, status bar) all take up valuable screen real-estate while not being very useful while talking to a Zimbra server. Following is a quick link I place in my browser toolbar that opens a separate resizable window and navigates to my Zimbra server.
Hope this comes in handy for someone else.
Code:
javascript:void(window.open('http://server/zimbra/mail','zimbraWindow','copyhistory=no,directories=no,location=no,menubar=no,toolbar=no,resizable=yes,status=no',false))