> ## Documentation Index
> Fetch the complete documentation index at: https://docs.heyy.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Delivery & failures

> Understand campaign delivery status per contact.

On the **campaign execution** page, each recipient (contact) has a delivery outcome—sent, delivered, failed, or other states your channel reports.

## Why failures happen

Common causes:

* [Contact subscription](/help/contacts/the-contact/contact-subscription) or opt-out
* Invalid or missing phone or channel identity
* WhatsApp template or policy issues—see [Message errors](/help/messaging-channels/whatsapp/message-errors)
* Channel disconnected or misconfigured—see [Common issues](/help/messaging-channels/whatsapp/common-issues)

Fix the underlying issue (template, channel, contact data) before retrying.

## Follow-up sends

After a run, you can target contacts who **failed** with a new campaign from the execution screen—without rebuilding the full audience from scratch. That workflow pairs with [Export & bulk actions](/help/campaigns-and-outreach/run/export-and-bulk-actions) when you need to update contact data first.

## Inbox and webhooks

Replies to campaign messages appear in [Inbox](/help/inbox/inbox-tour) like other conversations. Outbound campaign messages may include `campaign` / `campaignExecutionId` in [message webhooks](/webhooks/events/message-sent)—useful for integrations.