Exchange Mailbox Permissions

[jwood]

I am trying to modify permissions on Exchange 2003 so that domain admins, DON'T have unrestricted access to other users mailboxes.

I have left the permissions within system manager as defaults but added a deny permission for my each domain admin's own username.

For some reason admins can still access anyone's mailbox just by adding their username to the URL (we use OWA).