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

# TempInbox vs Mailtrap

> Honest comparison: Mailtrap's SMTP sandbox vs TempInbox's real-delivery inboxes — they test different things.

**Short answer:** these tools answer different questions. Mailtrap Email Testing is an **SMTP sandbox** — your app sends mail *into a trap* that never reaches a real recipient, so you can inspect content safely from staging. TempInbox is a **real inbox** — mail actually gets delivered over live SMTP. Use Mailtrap to inspect what your app *would* send; use TempInbox to prove the *end-to-end delivery path* works.

## Comparison

|                                           | TempInbox                                       | Mailtrap (Email Testing)                    |
| ----------------------------------------- | ----------------------------------------------- | ------------------------------------------- |
| Model                                     | Real inbox, real delivery                       | Sandbox — mail intercepted, never delivered |
| Tests real SMTP path                      | Yes — DNS, MX, queuing, spam filtering all real | No — bypasses real delivery by design       |
| Safe for "don't email real users" staging | Use unique test addresses                       | Yes — that's its core purpose               |
| HTML/spam analysis UI                     | No — parse `raw` yourself                       | Yes — preview, HTML check, spam score       |
| Price                                     | Free                                            | Free tier; paid plans for volume/teams      |
| API key                                   | None                                            | Required                                    |
| Account                                   | None                                            | Required                                    |
| E2E signup tests (Playwright/Cypress)     | Natural fit — form gets a real address          | Needs SMTP config pointed at the trap       |
| Production-config testing                 | Yes — no app changes needed                     | No — app must use sandbox SMTP credentials  |

## When Mailtrap wins

Pre-production content inspection: previewing templates, HTML rendering across clients, spam scoring — all *before* anything can leak to a real user. If your worry is "staging accidentally emails customers," a sandbox is the correct tool and TempInbox is not a substitute.

## When TempInbox wins

* **End-to-end truth**: Mailtrap can't tell you real delivery works — wrong DNS, broken MX, or a provider block never shows up in a sandbox. A TempInbox test fails when delivery actually fails.
* **No app reconfiguration**: your app sends through its normal production SMTP path; the test just supplies a TempInbox address in the form
* **Zero setup in CI**: no credentials, no sandbox host/port wiring — [CI guide](/guides/ci-pipeline)

## Use both

Mature pipelines often do: Mailtrap in staging for content/spam checks, TempInbox in E2E suites for the real-delivery signup flow. They overlap less than they compete.

## Related reading

* [Email for Testing: A Practical QA Playbook](https://tempinbox.dev/blog/email-for-testing) — choosing between sandboxes, mocks, and real inboxes
* [QA Workflows](/guides/qa-workflows) — end-to-end patterns with real delivery