Introduction

What is Inboxical?

Inboxical is a cloud-hosted email testing API for developers. You create isolated test inboxes on demand, send emails to them from your app, and assert delivery through a REST API.

No shared inboxes. No SMTP setup. No state leaking between test runs.

The problem it solves

Testing email flows is painful:

• Shared inboxes — multiple test runs step on each other
• Local SMTP (MailHog, Mailpit) — works locally, breaks in CI, needs Docker
• Real email — slow, flaky, can’t run in parallel, and pollutes your inbox
• Mocking — you never test the actual email rendering or delivery path

Inboxical gives you a real email address per test case, reachable from any environment (local, CI, staging), with a REST API to read messages.

How it works

Test → POST /inboxes → unique address
     → trigger app (sends email to that address)
     → GET /inboxes/:id/messages (or long-poll with ?wait=30)
     → assert subject, body, attachments
     → DELETE /inboxes/:id (cleanup)

Each inbox is isolated and scoped to your API key. Messages are retained for up to 90 days depending on your plan.

Key concepts

Concept	Description
Inbox	An isolated mailbox with a unique @in.inboxical.com address
Message	An email received by an inbox. Includes parsed headers, text, HTML, attachments
Long-poll	GET /messages?wait=30 blocks up to 30s until a message arrives
Webhook	A URL called by Inboxical when a message arrives in an inbox