Cloudflare Email Service

Your knowledge of the Cloudflare Email Service, Email Routing or Email Sending may be outdated. Prefer retrieval over pre-training for any Cloudflare Email Service task.

Cloudflare Email Service lets you send transactional emails and route incoming emails, all within the Cloudflare platform. Your knowledge of this product may be outdated — it launched in 2025 and is evolving rapidly. Prefer retrieval over pre-training for any Email Service task.

If there is any discrepancy between this skill and the sources below, always trust the original source. The Cloudflare docs, REST API spec, @cloudflare/workers-types, and Agents SDK repo are the source of truth. This skill is a convenience guide — it may lag behind the latest changes. When in doubt, retrieve from the sources below and use what they say.

Retrieval Sources

FIRST: Check Prerequisites

Before writing any email code, verify the basics are in place:

1. Domain onboarded? Run npx wrangler email sending list to see which domains have email sending enabled. If the domain isn't listed, run npx wrangler email sending enable userdomain.com or see cli-and-mcp.md for full setup instructions.
2. Binding configured? Look for send_email in wrangler.jsonc (for Workers)
3. postal-mime installed? Run npm ls postal-mime (only needed for receiving/parsing emails)

What Do You Need?

Start here. Find your situation, then follow the link for full details.

Quick Start — Workers Binding

Add the binding to wrangler.jsonc, then call env.EMAIL.send(). The from domain must be onboarded via npx wrangler email sending enable yourdomain.com.

// wrangler.jsonc
{ "send_email": [{ "name": "EMAIL" }] }

const response = await env.EMAIL.send({
  to: "[email protected]",
  from: { email: "[email protected]", name: "My App" },
  subject: "Welcome!",
  html: "\x3Ch1>Welcome!\x3C/h1>",
  text: "Welcome!",
});

The binding is recommended for Workers — no API keys needed. If a user specifically requests the REST API from within a Worker (e.g., they already have an API token workflow), that works too — see rest-api.md.

See sending.md for the full API, batch sends, attachments, custom headers, restricted bindings, and Agents SDK integration.

Quick Start — REST API

For apps outside Workers, or within Workers if the user explicitly requests it. Key differences from the Workers binding:

• Endpoint: POST https://api.cloudflare.com/client/v4/accounts/{account_id}/email/sending/send
• from object uses address (not email): { "address": "...", "name": "..." }
• replyTo is reply_to (snake_case)
• Response returns { delivered: [], permanent_bounces: [], queued: [] } (not messageId)

See rest-api.md for curl examples, response format, and error handling.

Common Mistakes

References

Read the reference that matches your situation. You don't need all of them.

• references/sending.md — Workers binding API, attachments, Agents SDK email. For Workers or Agents SDK.
• references/rest-api.md — REST endpoint, curl examples, error handling. For apps NOT on Workers.
• references/routing.md — Inbound email() handler, forwarding, replying, parsing. For receiving emails.
• references/cli-and-mcp.md — Domain setup, wrangler commands, MCP tools. For first-time setup.
• references/deliverability.md — SPF/DKIM/DMARC, bounces, suppressions, best practices.