Yes, multiple users may be added to the approved sender list for a specific user OR organizational-wide by using batch commands.  We can complete the batch command for you OR you can login to the Postini system as a system admin, select "Batch" and then select "Help" to view batch reference guides, summaries, and examples. If you would like for us to complete the task for you, please create a ticket at:  http://support.webservio.net and provide a list of the approved senders and let us know if it should be applied organizational-wide or just to specific users. Our engineering time to complete the task will be billable.