IM client single sign on with AD integration.

[Splat]

Currently we have zimbra NE installed and would like to roll out a IM client that attaches to the xmpp server zimbra provides. Our users are all using AD authentication within the domain and use there AD un/pw to log into their zimbra accounts. I was wondering if there is a IM client that will pass the windows credentials to the xmpp server to authenticate the users. The ideal solution would require zero intervention by the users and have the IM app start when they log in. Closest I have seen is Pandion (Pandion | An easy to use XMPP and Jabber client) Which says it has single sign on but it has very little documentation on implimentation. Spark I think will also work with quite a bit of hacking. Any suggestions would be greatly appreciated.

Thank you.