Why it exists

Disposable-email services were built for humans: a web UI, a copy button, and an inbox you refresh by hand. That's useless the moment the "user" is software — an AI agent that needs to sign up somewhere and read the verification code, or a QA pipeline that must assert on a password-reset email. MailHook treats inboxes as infrastructure instead: one POST creates an address, mail arrives parsed and signed via webhook or SSE, and the body is already JSON. 12.4M emails processed, 99.98% uptime, ~180ms median API response.

Main features

• One-call inbox creation — random addresses, custom slugs, or catch-alls on your own domain (paid tiers).
• Emails as JSON — sender, subject, body (text), and attachments captured and delivered structured; no MIME-parsing library required.
• Real-time delivery — signed webhooks the moment mail lands, or Server-Sent Events for streaming consumption; polling still available.
• Outbound sending (Business tier) — approved-list sending with 10K outbound emails/month, plus SMTP and email forwarding to your own inboxes.
• Multi-user-friendly — free tier for quick tests (random addresses, shared access); private API-key access from Pro up.
• Language-agnostic — plain REST, so any agent runtime, CI job, or script can drive it.

Who it's for

• Developers wiring AI agents that must complete real signup/verification flows end to end.
• QA and E2E test suites that need deterministic, assertable inboxes instead of a shared Gmail alias.
• Builders of verification and notification flows who want to receive (and later send) mail programmatically without running a mail server.
• Teams testing multi-user products where each simulated user needs its own isolated address.

How it compares

• Mailinator / Guerrilla Mail — classic disposable inboxes designed for eyeballing in a browser; MailHook is API-first with webhooks/SSE and structured payloads.
• Mailtrap / Mailhog / Mailosaur — testing mail servers focused on SMTP capture for CI; MailHook skips SMTP plumbing and delivers parsed JSON over HTTP, which suits agent workflows better.
• Self-run postfix + catch-all — ultimate control, real operational burden (deliverability, spam, parsing); MailHook outsources exactly that.
• temp-mail style sites — manual, rate-limited, no SLA; fine for one-off humans, wrong for automation.

Notes

• Free plan covers getting started: random addresses with shared access — don't use shared free inboxes for anything sensitive.
• Pro ($18/mo) adds custom subdomain, custom slugs, private API key access, and webhooks + SSE; Business ($300/mo) adds outbound sending and catch-alls; Scale ($1000/mo) adds bring-your-own domains and unlimited sending.
• Docs and a public changelog live on the site; sign-in required to generate live API keys.
• Because inboxes are disposable and often shared, treat them as public-ish: never route password resets of real accounts through them.

Useful links

• Official site: https://mailhook.co/
• Documentation: https://mailhook.co/docs
• Pricing: https://mailhook.co/pricing
• Blog: https://mailhook.co/blog