When a hard bounce or complaint arrives, your sending system records the address and skips it on later sends. This protects delivery reputation and prevents repeated sends after permanent failures or complaints.

## Which addresses belong on the list?

Add an address when a hard bounce shows that delivery is permanently failing, when a recipient reports spam, or when you block it manually. Keep the reason and origin with each entry so you can audit the decision. Store unsubscribe choices separately as preferences. They apply by message category.

Do not treat every temporary failure as a permanent suppression. A full mailbox or an unavailable receiving server can recover. Retry those temporary failures according to your delivery policy. Suppress an address only when the failure is permanent.

## Does a suppression apply to every message?

The scope depends on the reason. A hard-bounce or manual suppression blocks every send to that address. A complaint suppression blocks non-transactional mail while allowing a genuine password reset or other operational message.

Keep suppression state separate from your audience membership. Removing an address from a campaign does not prevent another workflow from sending to it.

## How should I maintain the list?

Apply suppressions before every send, including imported contacts and retry jobs. Preserve the first event and later updates when a record changes. That history shows why the address was blocked and prevents an import from erasing the decision.

Remove an entry only after you have corrected the cause and confirmed that your policy permits sending again. Do not remove a hard-bounce or complaint record merely because the address later accepts a probe. A successful probe does not prove that the original failure or complaint was resolved.

## How do I manage suppressions in Bird?

Before each send, check the Bird suppression list so your workflow skips recipients it must not contact. Bird creates records from hard bounces and complaints. The [suppressions guide](/docs/guides/email/suppressions) documents their fields, scopes, and management API.

Subscribe to suppression events if your own database needs the same state. Keep Bird's list authoritative for the delivery decision. Use your copy for reporting and workflow context.

## In short

- Suppress permanent failures, complaints, and manual blocks.
- Keep reason, origin, and event history with each entry.
- Retry temporary failures instead of suppressing them immediately.
- Check the list before every send and follow Bird's suppression guide.

## Related resources

- [Email deliverability](/products/email/deliverability) (product)
- [Deliverability · Email](/docs/guides/email/deliverability) (docs)
- [What happens between send and the inbox](/learn/email/what-happens-between-send-and-the-inbox) (video)
- [What are bounced emails?](/explained/deliverability/what-are-bounced-emails) (answer)

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