You cannot use the Global Address Book from a phone or in the Mail App on a Mac.

Imported ‘All Day Events’ from FirstClass come in as 12:00am-11:59pm and have to be manually flipped to ‘All Day’ in Zimbra.

You cannot email a Forum, you must go to the Forum to post.

For some people setting an email signature in Zimbra, will give an ‘Missing Value’ error, if you are having problems setting a signature use the Chrome web browser.