Thank you for your post.
I'm looking at the Business Productivity Solution database. When I click on Email, it opens the bps_Email file. The "Send" button executes the script "Send Campaign". Opening the "Send Campaign" script, towards the bottom, you'll see the script step:
Send Mail [ Send via E-mail Client; To: Campaigns_Contact Management globalID::Email;....
If you modify this script step, you will see empty CC and BCC settings. You can either put in static text or reference fields.
Let me know if you need clarification or help finding this script.