Not that I can see. There are some Google hits on discussions around 2006, but didn't see anything come of it.
1. can i integrate zimbra with kloxo ?
2.can i use zimbra without any panel just for mail services ?if yes how ?
Yes, but you'd have to use the Administrative Portal that's built into Zimbra for management. I'm not familiar with managed hosting, I've always just used my own servers.
Ben Franklin quote:
"Those who would give up Essential Liberty to purchase a little Temporary Safety, deserve neither Liberty nor Safety."