Zimbra Server Engineer Tim Brennan released a Firefox Extension that let’s you check email and lists your upcoming appointments. It’s called ZimbraCheck. He released this a few months ago on the forums but we wanted to make sure a wider audience got access to it.
Here’s partial quote of his release notice.
I cobbled together a really simple little Firefox extension that periodically checks the server and puts a notification in the statusbar if there is new mail. The notification is clickable: it brings up a popup menu with the titles of the first 10 new messages in your account — and if you’re runnining v4.5 or later — choosing an entry from the menu can take you directly to the message in the HTML client (unfortunately there’s no direct-to-message URL support for the Ajax client, so clicking on a menu entry just takes you to the client).
You can install it from: http://curple.com/zimbracheck/
The rest of his post and comment/suggestions can be made on on this Zimbra forum thread.