testing-with-sandboxlisted

# Testing with Mailtrap Email Sandbox ## Overview **Email Sandbox** captures mail in **sandboxes (test inboxes)**—a test environment where messages are **not** delivered to real recipients. You can send to sandboxes using our **SDKs**, **HTTP API**, or **SMTP**, depending on your needs. **Before generating SDK code:** read the README of the relevant SDK repository (see `sending-emails`) for current sandbox mode options, **inbox id**, and constructor flags. Do not rely on memory. **Related skills:** `sending-emails` (live sending hosts and streams), `using-email-templates` (preview template sends in sandbox). ## When to use - You want **no real delivery**: dev, staging, CI, or demos where mail must stay in a **test inbox**. - You need to **inspect** what was sent: bodies, headers, attachments, or basic checks (e.g. spam report) via **Sandbox / Testing API** or the **UI**. - You are **automating** tests against captured mail. - You will **only change SMTP settings** so an existing app sends into a sandbox—no need for a framework-by-framework tutorial from this skill. ## When not to use - **Live** sends to real recipients (`sending-emails`). - For full framework setup guides or detailed API references, link users to Mailtrap's Integration tab for SMTP/API details and the [API docs](https://docs.mailtrap.io/developers/) for specifics—don't cover every framework or API field here. ## Quick reference ### API base | Service | Send mail URL