Thank you for your response Tammy, but I'm at a complete loss as to why it's not feasible to work this into Exchange 2010 via service pack? I wrote a Windows service in C# to handle synchronization of DL managers based on AD group membership in under a month. All while performing other project related tasks. You are Microsoft. You wrote Exchange. You wrote AD. You already wrote this functionality before. You have and are the technology. The functions required all lie within the platform SDK and/or .Net framework to be easily leveraged by even the greenest of programmers. Almost all other AD integrated Microsoft programs are completely capable of handling group membership based authorization, nesting and all. Group based based management is a core concept of delegation, reduced administration overhead, and support costs. What can we do as faithful Microsoft customers to get this functionality bumped up and added to Exchange 2010? We're just asking for a bit of your time to make Exchange Administrators around the world breathe a little easier.