Please follow one of the below options that suits the business need:
1) Set up the Global Notification in the NetVault Server (NV) only which will send an email to a single email server on the exchange server and let the Exchange server handle all of the forwarding based on rules and conditions.
2) Set up the Global Notification in the NV Server only and modify the Mail scripts on the NV server to handle all of the forwarding based on rules and conditions set on the scripts that will be run by NV SERVER;
3) Set up the Global Notification in the NV Server AND the NV Clients and use pre and post scripts that are placed on the NV server AND on the Clients to handle all of the forwarding based on rules and conditions set on the scripts that will be run by the NV SERVER and CLIENT.