The “BCC Email Address” is the one to be used when sending bcc emails.
In the search bar enter “Astral Send Setup” and select it from the list:
Figure 1 | Business Central Search - Astral Send Setup
On the Astral Send Setup Page, on the Email FastTab, enter the BCC Email that all documents will be sent to:
Figure 2 | Astral Send Setup
Please be aware that all documents sent via Astral Send will be bcc’d to the email address you setup here.