Shared recipient fields are intended for genuine group correspondence, not list distribution. Exposing addresses in To or Cc is an obvious privacy failure, while Bcc still makes per-recipient unsubscribe, bounce correlation and complaint investigation unnecessarily difficult.
What individual delivery enables
- A visible To address that matches the recipient.
- Unique unsubscribe and preference links.
- Accurate suppression of bounced or complaining addresses.
- Safe personalisation without disclosing other recipients.
- Clear consent and communication history.
Individual messages may still be submitted efficiently using a queue and controlled concurrency. AuthSMTP account limits and recipient guidance are described in our recipient FAQ and connection guidance.
Do not create a single enormous Bcc message merely to reduce API or SMTP submissions. It transfers operational complexity into a message that is harder to diagnose and manage responsibly.
For list mail, generate and submit one independently addressed message for each recipient.
Inspect a received campaign message and confirm that it contains one intended recipient, a recipient-specific unsubscribe route and a correlation identifier your system can trace.