Part of the problem is that a lot of the technology (and terminology) is a hold-over from NT 4. In NT 4 it was recommended (for security reasons) that each department have it's own domain. Which most of us feel is rather silly today. http://www.rhyshaden.com/nt_grp.htm will explain some of the older group theory. Here is an excerpt: "Local Groups are used to grant permissions to users to access network resources and perform certain system tasks. There are some built-in local groups. Global Groups are used to organize user accounts typically used in multi-domain networks where users need to access resources in different domains. They are always created on the PDC in the domain where the account resides. You cannot place global groups into global groups nor can you place local groups into local groups. You can put global groups into local groups. A good rule is Accounts -> Global -> Local -> Permissions." Steve Iltis Metal Exchange Corporation (314) 434-3500 x166 -----Original Message----- From: exchangelist-bounce@xxxxxxxxxxxxx [mailto:exchangelist-bounce@xxxxxxxxxxxxx] On Behalf Of Jabber Wock Sent: Friday, June 30, 2006 8:20 AM To: [ExchangeList] Subject: [ExchangeList] understanding distribution groups Hi all, I am trying to get an understanding of Exchange distribution groups. While I understand these in a cursory way, I just do not seem to be able to find a satisfactry answer to these questions: a) What is the difference between Domain Local, Global, and Universal distribution groups? When would I use each type? When would I *NOT* use each type? b) What is the difference between a "Security" group and a "Distribution" group exactly? What does one do that the other does not? When would I use one versus the other? (the one thing I do understand is query based distribution groups, and there seems to be plenty of documentation around on that topics). Everywhere I have looked, it seems that there is a broad assumption that everyone knows what these are. It is almost as if the differences between these are arbitrary and you can use any of the above in any situation. Surely that is not true, so I am trying to get a clearer understanding of these concepts. Any assistance or links to tutorials on this topic would be greatly appreciated. Mike