Hi,
I don't know if this is the correct place to mention this - but anyway, here are my two pennies.
Signing up for email alerts at
http://www.zimbra.com/alerts/index.php does not work if you have a domain name under the top level ".name". The website rejects your subscription with the message "Email address is not valid."
Regarding the Zimbra server I just want to say: wow, what a really great stuff (well still some bugs here and there but hey, it's only beta)