Is there a way to look in Exchange 2007 to tell if I am using the Enterprise CAL or Standard CAL. on some properties tab i get a message that says "...is a premium feature and requires an Exchange Enterprise CAL" to enable it.I thought we bought the enterprise CALs to begin with but am not sure.

You wont be able to tell by looking at the Exchange Server. THe only real way to know is to check with your licensing rep.

Is there a way that the exchange server can tell which CALs we are using inorder to deny us access to those enterprise features?I am still trying to locate the invoice for that purchase to verify. I would like to remain in compliance.

Nope. Your use or enabling of those Enterprise CAL features means you have purchased the required licenses.http://www.microsoft.com/exchange/2007/evaluation/editions.mspx

Ok Thanks.