running Exchange server 2003 enterprise ed., users can now view other user's calendars or inbox without delegate permissions. it's certainty that there was some configuration change that caused this. any suggestions for correcting or troubleshooting, a microsoft kb would be helpful..

I am not familar with any KB that might be helfpul in solving this, but has anyone manually assigned permissions to your Exchange organization? As an administrator, can you open Outlook and view other user's mailboxes? It is possible someone has delegated a group full control permissions to the admin group or the organization. First, you need to enable the Security tab on your Exchange System Manager. See this article: http://support.microsoft.com/kb/259221 Next, look at the Administrative Group and the organization objects and see if any users or groups have been manually delegated "Full Control" to those container. Normally "Send As" and "Receive As" are blocked, but someone can override that.