I could not find any way to see how you could add an IP address as a ‘white list’ for our Postini installation. Mails coming from our mailing list manager kept getting caught in the Postini spam interface (which is probably a whole other issue, which I will need to address later).
To get Postini to white list an IP address, you need to go into the Batch editing mode and issue this command:
addallowedip organization name,domain.com:10.0.0.0
See page 30 for ‘addallowedip’ syntax and more information.