Sure, there's actually multiple ways to get to it, here's a few-
In the admin console:
Hit the help tab (blue question mark on left) > then click 'About Zimbra Version'
Via the command line:
Code:
su zimbra
zmcontrol -v
Or in the main search bar of the advanced (ajax) web-client enter:
While we currently have some display of this disabled, you can also add it to your profile>
http://www.zimbra.com/forums/profile.php?do=editprofile > about halfway down the page 'additional information' > zimbra version blank