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

# Sandbox Channels

> Set up dedicated Channels for testing.

Sandbox Channels are your safe, self-contained space to develop and test email integrations without sending to real inboxes.
A Sandbox Channel behaves exactly like a regular Channel—you can send through the API or SMTP, inspect messages, trigger webhooks, and check stats—except the emails never leave Helo.

## When to use a Sandbox Channel

Sandbox Channels are good for:

* **Building your integration** - Test your API calls, SMTP setup, and payload formatting without worrying about test emails landing in someone's inbox.
* **Checking templates** - Send real messages through the API and inspect them in the Helo dashboard to confirm they are working correctly.
* **Testing webhooks** — Sandbox messages trigger delivery webhooks just like live messages do, so you can build and test your webhook handlers end-to-end.
* **Supporting QA and staging environments** — Point your staging app at a Sandbox Channel so your team can test freely without any risk.

<Info>
  **Tip:** Create [API credentials](/core/credentials) that work with your Sandbox Channel. When setting up new API credentials, you can decide to scope them to a single Channel only. Set up dedicated credentials that work with your Sandbox environment only to further isolate your testing environments.
</Info>

## How Sandbox Channels work

Sandbox Channels process messages through Helo's infrastructure the same way live sends do. That means:

* Messages show up as Delivered in your dashboard and via the API (even though we don’t actually deliver them to real inboxes)
* All message metadata (headers, recipient, subject, body) is stored and inspectable
* Delivery webhooks fire normally
* Bounce simulation is supported (see [simulating bounces](/core/bounces#simulating-bounces))

<Info>
  **Heads up:** Because Sandbox messages are processed through Helo's infrastructure, they do count toward your monthly sending budget, just like live messages.
</Info>