Default SMTP: user@123.com Other SMTP: user@xyz.com When we change the setting of a user to set his primary SMTP as @xyz.com all works fine except that he gets error message (Task MS Exchange reported error (0X8004010F): The operation failed. An object cannot be found) while downloading address book on WAN IP (Caching enabled or not); this works fine on LAN. It works fine if the user's primary SMTP is set to @123.com Any suggestions what changes do we need to make and where