Hi, All It's OK using command line "Dir \\.\BackOfficeStorage\mydomain.com\mbx" in Exchange 2003(32-bit), but cannot access it in Exchange 2007(64-bit) that co-exist with the Exchange 2003(32-bit).[I use domain administrator account] My Questions: 1. Does Exchange 2007 support "Dir \\.\BackOfficeStorage\mydomain.com\mbx" ? 2. Will be OK in Exchange 2007 with registering event sink script? cscript c:\\exch\\RegEvent.vbs add "onsave;ondelete" "COM+ for Exchange Event Sink" "file://./backofficestorage/mydomain.com/mbx/<mailbox-account>/Calendar/CalendarEventSink" -m exact Itshow "Error Opening Record : -2147024891 Access denied" in my environment. 3. ExchMailAdmin is Exchange 2003 Admin,and is Exchange 2007 Org Admin, ExchMailAdmin can access every Exchange 2003 mailboxes with http://mail.mydomain.com/exchange/<mailbox-account>/,but cannot access the mailboxes migrated to Exchange 2007.WhatI needto do more? Thanks & Regards,

Question 3 Answer: add-mailboxpermission "<mailbox-account>" -accessRights FullAccess -user mydomain\ExchMailAdmin