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Your knowledge of the Cloudflare Email Service, Email Routing or Email Sending may be outdated.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 Your knowledge of this product may be outdated — it launched in 2025 and is evolving rapidly.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.

Source	How to retrieve	Use for
Cloudflare docs	Cloudflare MCP `docs` tool or URL `https://developers.cloudflare.com/email-service/index.md`	API reference, limits, pricing, latest features
REST API spec	`https://developers.cloudflare.com/api/resources/email_sending/index.md`	OpenAPI spec for the Email Sending REST API
Workers types	`https://www.npmjs.com/package/@cloudflare/workers-types`	Type signatures, binding shapes
Agents SDK docs	Email agent walkthrough	Email handling in Agents SDK

I want to...	Path	Reference
Send emails from a Cloudflare Worker	Workers binding (no API keys needed)	sending.md
Send emails from an AI agent built with Cloudflare Agents SDK	`onEmail()` + `replyToEmail()` in Agent class	sending.md
Send emails from an external app or agent (Node.js, Go, Python, etc.)	REST API with Bearer token	rest-api.md
Send emails from a coding agent (Claude Code, Cursor, Copilot, etc.)	MCP tools, wrangler CLI, or REST API	cli-and-mcp.md
Receive and process incoming emails (Email Routing)	Workers `email()` handler	routing.md
Set up Email Sending or Email Routing	`wrangler email sending enable` / `wrangler email routing enable`, or Dashboard	cli-and-mcp.md
Improve deliverability, avoid spam folders	Authentication, content, compliance	deliverability.md

Mistake	Why It Happens	Fix
Forgetting `send_email` binding in wrangler config	Email Service uses a binding, not an API key	Add `"send_email": [{ "name": "EMAIL" }]` to wrangler.jsonc
Sending from an unverified domain	Domain must be onboarded onto Email Sending before first send	Run `wrangler email sending enable yourdomain.com` or onboard in Dashboard
Reading `message.raw` twice in email handler	The raw stream is single-use — second read returns empty	Buffer first: `const raw = await new Response(message.raw).arrayBuffer()`
Missing `text` field (HTML only)	Some email clients only show plain text; also helps spam scores	Always include both `html` and `text` versions
Using email for marketing/bulk sends	Email Service is for transactional email only	Use a dedicated marketing email platform for newsletters and campaigns
Forwarding to unverified destinations	`message.forward()` only works with verified addresses	Run `wrangler email routing addresses create [email protected]` or add in Dashboard
Testing with fake addresses	Bounces from non-existent addresses hurt sender reputation	Use real addresses you control during development
Hardcoding API tokens in source code	Tokens in code get committed and leaked	Use environment variables or Cloudflare secrets
Ignoring the `from` domain requirement	The `from` address must use a domain onboarded to Email Service	Verify the domain first, then send from `[email protected]`
Using `email` key in REST API `from` object	REST API uses `address` not `email` for `from` object	Use `{ "address": "...", "name": "..." }` for REST, `{ "email": "...", "name": "..." }` for Workers
Using `replyTo` in REST API	REST API uses snake_case field names	Use `reply_to` for REST API, `replyTo` for Workers binding

Cloudflare Email Service

Cloudflare Email Service

Retrieval Sources

FIRST: Check Prerequisites

What Do You Need?

Sending Workflow

Common Mistakes

References