I have not used Xobni myself, but I think if I have implemented a plug in for Outlook, offered $20M by Microsoft for it, I will take the money and run as fast as I can.
Outlook is a Microsoft product, they have unlimited resources, they understand Outlook itself better than anyone outside. Hey this guys can replicate the plug in really fast time trust me.
I’m a consultant and done stuff for them I know some of the people there; a bunch of really smarts hackers.