I have been running Zimbra NE for a little over a week now. My users are happy and everything is going smooth.
Once small issue though. When I log into the admin console and look at the accounts, the Last Login Time section isn't always updated. Some users are shown as logging in today, while others aren't. I know for a fact some of these users have logged in today. It says the last time I logged in was 2 days ago, but I'm logged in right now.