Thank you for using the Support Forum. I am not aware of a way to restrict the e-mail to only entries in the address book. But please consider contacting your support centre to confirm that this is not possible.
If you have access to the mail-server, this could probably be set up there, you could block the email the printer is using from sending to others that are not in a specific white-list.
Hope this helps
hello, my understanding is that this is controlled by your email server and the security in place on it.