I'm thinking about using Zimbra for a small number of users (less than 100). Can Zimbra lived on a shared server also using apache to serve web pages, or does it grab too many resources? I'm not worried about the mail servers, but I know Java web apps tend to like to get as much memory as they can and hold on to it and I didn't know if Zimbra was designed so that it could be used on a shared box (maybe starting Tomcat with a low recommended memory value), or if it needs to be on its own box.