When we tried to use the Live Demo account, we opened the link Live demos of Zimbra's open source email and group calendar software. We filled the required information and then when we clicked on Submit button, it opens some page, say starting page which asks for CAPTCHA code. And, when we try by entering the given captcha code it doesn't go further. We keep on trying twice-trice and more then ten times but still no response with next link or other page.
Let me know is there any issue with your live demo account.