I've got several Server 2008 R2 boxes running XenApp 6.0 and I've discovered a minor problem... IE has decided that my regular users don't have cookies enabled and so they cannot use the Zimbra web interface.

No problem, thought I... I figured that it was just a change to a more poranoid way of thinking in IE and that I'd have to force the acceptance of cookies via a GPO. Can I find how to do this though?

Please help!