Add Machine Inbox to the service directory

[timalander]

Task-scoped, self-expiring email inboxes for agents, paid through Stripe MPP: $2.00 buys a seven-day replyable address ($5.00 pro tier for thirty days, $1.00 extension), with parsed MIME, attachments, and replies restricted to authenticated inbound senders.

[vercel]

@timalander is attempting to deploy a commit to the Tempo Team on Vercel.

A member of the Team first needs to authorize it.

[github-actions]

🔀 Changed Services

✅ Added

• machine-inbox

[github-actions]

Thanks for submitting a service to the MPP directory!

If you want your service included in the curated mpp.dev/services list, complete this checklist before review:

Required

• Your service is live and accepting payments via MPP (not a placeholder or coming-soon)
• You've added your entry to schemas/services.ts following the contributing guide
• Types pass: pnpm check:types
• Build succeeds: pnpm build

Recommended

• Register your service on MPPScan (by Merit Systems) — it follows the standard MPP discovery format and makes your service discoverable by agents immediately, no PR required

Review criteria

We prioritize services that are high quality and novel. We may not approve services that duplicate existing functionality or aren't yet production-ready.

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Contributing guide · MPPScan · Protocol docs

[timalander]

Checklist

• Live and accepting payments via MPP — npx mppx@latest validate https://machineinbox.com passes 16 checks, 0 failures, against the production deployment
• Entry added to schemas/services.ts
• Types pass — schemas/services.test.ts green locally (9,400 assertions)
• Build succeeds — pnpm build green locally
• Registered on MPPScan (in progress)

What makes this novel

The directory already lists two email services, and Machine Inbox deliberately overlaps with neither:

• AgentMail is a full inbox platform (accounts, domains, webhooks). StableEmail is pay-per-send delivery and relay addresses. Machine Inbox is task-scoped, self-destructing email: one flat MPP purchase ($2.00/seven days, $5.00 pro/thirty days, $1.00 extension) creates an address that lives exactly as long as the job and then hard-deletes its mail and credentials. No accounts, API keys, or subscriptions — the receipt is the account.
• Structurally spam-proof outbound: the service cannot originate email. Replies can only go to a sender whose inbound message passed SPF/DKIM/DMARC alignment recorded by Cloudflare, with no CC/BCC/attachments and Auto-Submitted headers on every send — so listing it adds receive-and-reply capability to the ecosystem without adding an abuse vector.
• Fully machine-legible: openapi.json with MPP offers on every paid route, llms.txt, meta.json, A2A agent card with prices, and runnable examples covering the raw 402 flow and the post-purchase read/reply loop.