I have a customer with a SBS2003 system hosting their own mail on Exchange. Recently we have found that we cannot turn off the sharing of their inbox. The default permissions in Outlook 2003 is set to none and I believe everything is setup properly under the Exchange Advanced tab. I have deny read permissions set for all users but only a handful of users are non-accessable. All users are members of the same groups and nothing special. If I deny full mailbox access to the everyone group, no one is able to log into the domain and I'm just not knowledgeable of all of the "rights". Can someone please get me out of this? I am afraid I am going to lose this customer.