No. Multiple inboxes do not affect auto BCC behavior.
How auto BCC works with multiple inboxes
The same BCC address is applied to all connected inboxes
Emails sent from any inbox are synced to your CRM consistently
No per-inbox configuration is required
This ensures reliable CRM logging even when sending at scale.
To set or update BCC, see Add an Auto BCC to Emails Sent from Salesgear.