Just downloaded this thing. They are comparing it with Outlook and Thunderbird. Took me a while to figure out why it wouldn't load and showed Prism dialog. Turns out it must be changed to admin access to be launched on Vista or Windows 7. XP is 7 years old!
Imagine Outlook or Thunderbird installing, not working, then making the user figure out they need to change some admin thingy. Not wonder I hadn't heard of Zimbra Desktop before.
So how can we encourage these folks to make a real consumer app and spread the word? The calendar & contact sync with gmail mean it could be a real winner!