I'd like to try Zimbra, but I'm concerned that it will interfere with other software I have running on the server. The server I have is running my web pages using Apache 2, MySQL and Postnuke. Will Zimbra mess this installation up? Does it require a server all to itself?

Why must I disable firewalls prior to install? My server is connected to the web and I don't want it runnng without firewalls even for a moment. Would it not be just as easy to tell me what ports Zimbra uses and let me open those and leave the others closed? How can I set up firewalls later if I don't know what ports it uses? I looked through the Admin Guide and the only port I saw specifically mentioned was 7071 for web administration although I assume it uses the standards for POP, IMAP and SMTP connections. I also assume, based on another forum post that 7777 needs to be open.