Postey

Self-hosted email for apps and agents, installed into your own Cloudflare account.

Postey is two products in one dashboard: Send — a Resend-compatible transactional email API — and Inbox — replies and inbound mail, threaded to the sends they answer. A deploy wizard on the marketing site provisions prebuilt Worker bundles, D1 migrations, and the dashboard directly into your Cloudflare account, so your email infrastructure runs entirely under your own control. Same install model as Traks.

Highlights

• Resend-compatible API — drop-in /emails endpoint that works with Resend's SDKs; switch providers by changing the base URL and key.
• Two-way email — every sending domain can also receive. Replies are parsed, stored with their attachments, and threaded to the outbound send they answer — rendered mail-client-clean (inline images included) in the same dashboard.
• Agent-native — a built-in MCP server gives coding agents their own email tools: send, plus list_replies / get_reply / get_reply_attachment / reply_to to close the loop on conversations, files included.
• Honest delivery — sends go inline through Cloudflare Email Service, so the API response is Cloudflare's real answer (200 sent; 429 with Retry-After when the reputation-gated cap hits). No queue pretending a send succeeded.
• The product layer Email Service lacks — API keys (hashed, domain-scopable), idempotency, an email log with rendered previews and per-recipient status, templates with test sends, an auto-fed suppression list, and signed outbound webhooks.
• Self-hosted, your account, your data — everything lives in your Cloudflare account: Workers, D1, R2. Postey has no server-side access to your mail.

How it works

Send

Cloudflare Email Service (beta; Workers Paid: 3,000 emails/mo included, then $0.35/1k) handles delivery, DKIM signing, and IP reputation. Postey adds the product layer on top:

• Resend-compatible REST API (including /emails for their SDKs)
• API keys — hashed at rest, scopable per domain
• Idempotency — retrying a failed send re-attempts it safely
• Email log with rendered previews and per-recipient delivery status
• Templates with test sends
• Suppression list, auto-fed by bounces, complaints, and unsubscribe mail
• Signed outbound webhooks for delivery events, with one-click test deliveries
• MCP server for agents

Deliberately not built: scheduling, queues, and quota modeling — the reputation-gated daily cap is per-account and unknowable, so Cloudflare's own rejection is the only honest signal, and Postey passes it straight through.

Inbox

One catch-all Email Routing rule per zone (a deliberate, human step — Postey never touches your mail routing itself) delivers to the inbound Worker. Addresses like support@ become instant rows in Postey; unknown addresses keep bouncing. Replies are parsed (postal-mime), stored (D1 + R2, attachments included), threaded to the outbound send they answer via References, and announced with an email.reply.received webhook. The dashboard renders the conversation inline — sanitized HTML, cid: images resolved, quoted history collapsed — and replies as the receiving address through the same send pipeline; agents do the same over MCP. Setup is verified honestly: a DNS check confirms Email Routing is enabled, and a self-probe (the instance emails itself) proves the catch-all really delivers to the worker.

Repository layout

apps/
  home/
    web        postey.app marketing site + deploy/update/destroy wizard UI
    api        deploy wizard backend, instance registry, release manifests
  platform/    what gets installed into the customer's Cloudflare account
    api        dashboard API — sessions, domains, keys, templates, logs, Inbox
    send       public send API Worker (Resend-compatible REST + MCP server)
    inbound    Email Routing handler — stores inbound mail, threads replies,
               auto-suppresses unsubscribes
    web        dashboard SPA — Send and Inbox behind one product switcher
packages/
  shared       types + zod schemas for send payloads and webhook events
installer/     build-release / upload-release / release tooling

Monorepo managed with Bun workspaces + Turborepo. Requires Node ≥ 20.

Installing (deploy wizard)

The wizard on the marketing site installs Postey into your Cloudflare account. Constraints to know:

• Workers Paid plan required — the wizard verifies the subscription before proceeding.
• Domain onboarding is one manual step — Email Sending has no public API yet (dashboard-only while in beta). The wizard automates everything else, deep-links the step (dash.cloudflare.com → Email Service → Onboard Domain), detects completion by polling the zone's DNS for the locked cf-bounce records, and verifies with a free send to a verified address.
• Inbox's catch-all rule is likewise manual by design, guided from the dashboard's Inbox first-run screen — Postey never modifies your mail routing on its own.

Development

bun install
bun run dev          # all apps on :6010-:6014
bun run build
bun run type-check
bun run release:build && bun run release:upload   # publish a release

Contributing

Issues and pull requests are welcome. Please run bun run build and bun run type-check before opening a PR and keep changes focused.

License

MIT © 2026 Shivaprasad Manupadi