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: authorizing-api-requests (sandbox token scope, env vars, account_id resolution), 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