KyaPanel with Zimbra
It's an extremely useful tool, just to 'disclaimer': Zimbra can play well with others through APIs. That's how cross interactions for webservices/applications work best. Hacking mysql and localconfig could result in problems down the road and it would be negligent of us not to warn. (e: Zimbra can be managed by others, as as we're based some excellent open source third parties. It's up to the users to take the chance of course, just need to make sure our "what's NE supported" position is clear.
More specifically there are tools like zmlocalconfig/zmltmpinject/zmmailbox that could be used. example: http://www.zimbra.com/forums/administrators/26431-kyapanel-offers-zimbra-backup-restore-tool.html#post125101