---
id: secondsky/claude-skills/cloudflare-email-routing
version: "fc14ab18"
license: MIT
install: manual
updated: 2026-07-25
---

# cloudflare-email-routing — This skill guides you through Cloudflare Email Routing for both receiving emails via Workers and sending from verified addresses. Learn to parse incoming messages, implement allowlists and blocklists, route based on content, and handle attachments—all free and production-tested.

Publisher: secondsky · Stars: 196 · Updated: 2026-07-25

Install (manual): `git clone https://github.com/secondsky/claude-skills`

## SKILL.md

# Cloudflare Email Routing

**Status**: Production Ready ✅ | **Last Verified**: 2025-11-18

---

## What Is Email Routing?

Two capabilities:

1. **Email Workers** - Receive and process incoming emails (allowlists, forwarding, parsing)
2. **Send Email** - Send emails from Workers to verified addresses

Both **free** and work together for complete email functionality.

---

## Quick Start (10 Minutes)

### Part 1: Enable Email Routing

**Dashboard setup:**
1. Dashboard → Domain → **Email** → **Email Routing**
2. **Enable Email Routing** → **Add records and enable**
3. Create destination address:
   - Custom: `hello@yourdomain.com`
   - Destination: Your email
   - Verify via email
4. ✅ Basic forwarding active

### Part 2: Receiving Emails (Email Workers)

**Install dependencies:**

```bash
bun add postal-mime@2.5.0 mimetext@3.0.27
```

**Create email worker:**

```typescript
// src/email.ts
import { EmailMessage } from 'cloudflare:email';
import PostalMime from 'postal-mime';

export default {
  async email(message, env, ctx) {
    const parser = new PostalMime.default();
    const email = await parser.parse(await new Response(message.raw).arrayBuffer());

    console.log('From:', message.from);
    console.log('Subject:', email.subject);

    // Forward to destination
    await message.forward('you@gmail.com');
  }
};
```

**Configure wrangler.jsonc:**

```jsonc
{
  "name": "email-worker",
  "main": "src/email.ts",
  "compatibility_date": "2025-10-11",
  "node_compat": true  // Required!
}
```

**Deploy and connect:**

```bash
bunx wrangler deploy
```

Dashboard → Email Workers → **Create address** → Select worker

### Part 3: Sending Emails

**Add send email binding:**

```jsonc
{
  "name": "my-worker",
  "main": "src/index.ts",
  "compatibility_date": "2025-10-11",
  "send_email": [
    {
      "name": "SES",
      "destination_address": "user@example.com"
    }
  ]
}
```

**Send from worker:**

```typescript
import { EmailMessage } from 'cloudflare:email';
import { createMimeMessage } from 'mimetext';

const msg = createMimeMessage();
msg.setSender({ name: 'App', addr: 'noreply@yourdomain.com' });
msg.setRecipient('user@example.com');
msg.setSubject('Hello!');
msg.addMessage({
  contentType: 'text/plain',
  data: 'Email body here'
});

const message = new EmailMessage(
  'noreply@yourdomain.com',
  'user@example.com',
  msg.asRaw()
);

await env.SES.send(message);
```

**Load `references/setup-guide.md` for complete walkthrough.**

---

## Critical Rules

### Always Do ✅

1. **Enable node_compat: true** for postal-mime
2. **Verify destination addresses** before sending
3. **Parse with postal-mime** for email content
4. **Use mimetext** for creating emails
5. **Check message.from** for allowlists
6. **Forward with message.forward()** (not manual)
7. **Handle errors** (email delivery can fail)
8. **Test with real emails** (not just dashboard)
9. **Add MX records** (automatic via dashboard)
10. **Log email activity** for debugging

### Never Do ❌

1. **Never skip node_compat** (postal-mime requires it)
2. **Never send without verification** (delivery fails)
3. **Never hardcode email addresses** in public code
4. **Never skip parsing** (raw email is hard to work with)
5. **Never ignore spam** (implement allowlists/blocklists)
6. **Never exceed Gmail limits** (500 emails/day to Gmail)
7. **Never skip error handling** (emails can fail)
8. **Never modify DNS manually** (use dashboard)
9. **Never expose email content** in logs (PII)
10. **Never assume instant delivery** (email is async)

---

## Common Patterns

### Allowlist

```typescript
const allowlist = ['approved@domain.com'];

if (!allowlist.includes(message.from)) {
  message.setReject('Not on allowlist');
  return;
}

await message.forward('you@gmail.com');
```

### Blocklist

```typescript
const blocklist = ['spam@bad.com'];

if (blocklist.includes(message.from)) {
  message.setReject('Blocked');
  return;
}

await message.forward('you@gmail.com');
```

### Reply to Email

```typescript
const msg = createMimeMessage();
msg.setSender({ addr: 'noreply@yourdomain.com' });
msg.setRecipient(message.from);
msg.setSubject(`Re: ${email.subject}`);
msg.addMessage({
  contentType: 'text/plain',
  data: 'Thanks for your email!'
});

const reply = new EmailMessage(
  'noreply@yourdomain.com',
  message.from,
  msg.asRaw()
);

await env.SES.send(reply);
```

### Parse Attachments

```typescript
const parser = new PostalMime.default();
const email = await parser.parse(await new Response(message.raw).arrayBuffer());

for (const attachment of email.attachments) {
  console.log('Filename:', attachment.filename);
  console.log('Type:', attachment.mimeType);
  console.log('Size:', attachment.content.byteLength);
}
```

### Custom Routing Logic

```typescript
async email(message, env, ctx) {
  const parser = new PostalMime.default();
  const email = await parser.parse(await new Response(message.raw).arrayBuffer());

  // Route based on subject
  if (email.subject.includes('[Support]')) {
    await message.forward('support@yourdomain.com');
  } else if (email.subject.includes('[Sales]')) {
    await message.forward('sales@yourdomain.com');
  } else {
    await message.forward('general@yourdomain.com');
  }
}
```

---

## Email Message Properties

### Incoming Messages (ForwardableEmailMessage)

```typescript
message.from        // Sender email
message.to          // Recipient email
message.headers     // Email headers
message.raw         // Raw email stream
message.rawSize     // Size in bytes

// Methods
message.forward(address)        // Forward to address
message.setReject(reason)       // Reject email
```

### Parsed Email (PostalMime)

```typescript
email.from          // { name, address }
email.to            // [{ name, address }]
email.subject       // Subject line
email.text          // Plain text body
email.html          // HTML body
email.attachments   // Array of attachments
email.headers       // All headers
```

---

## Top 5 Errors Prevented

1. **"Email Trigger not available"**: Enable node_compat: true
2. **Destination not verified**: Verify all send destinations
3. **Gmail rate limit**: Max 500 emails/day to Gmail
4. **SPF permerror**: Use dashboard to configure DNS
5. **Worker call failed**: Check logs for parsing errors

---

## Use Cases

### Use Case 1: Support Ticket System

```typescript
async email(message, env, ctx) {
  const parser = new PostalMime.default();
  const email = await parser.parse(await new Response(message.raw).arrayBuffer());

  // Create ticket in database
  await env.DB.prepare(
    'INSERT INTO tickets (email, subject, body, created_at) VALUES (?, ?, ?, ?)'
  ).bind(message.from, email.subject, email.text, Date.now()).run();

  // Send confirmation
  const msg = createMimeMessage();
  msg.setSender({ addr: 'support@yourdomain.com' });
  msg.setRecipient(message.from);
  msg.setSubject('Ticket Created');
  msg.addMessage({
    contentType: 'text/plain',
    data: 'Your support ticket has been created.'
  });

  const confirmation = new EmailMessage(
    'support@yourdomain.com',
    message.from,
    msg.asRaw()
  );

  await env.SES.send(confirmation);
}
```

### Use Case 2: Email Notifications

```typescript
export default {
  async fetch(request, env, ctx) {
    // User signup
    const { email, name } = await request.json();

    const msg = createMimeMessage();
    msg.setSender({ name: 'App', addr: 'noreply@yourdomain.com' });
    msg.setRecipient(email);
    msg.setSubject('Welcome!');
    msg.addMessage({
      contentType: 'text/html',
      data: `<h1>Welcome, ${name}!</h1>`
    });

    const message = new EmailMessage(
      'noreply@yourdomain.com',
      email,
      msg.asRaw()
    );

    await env.SES.send(message);

    return new Response('Welcome email sent!');
  }
};
```

### Use Case 3: Email Forwarding with Filtering

```typescript
async email(message, env, ctx) {
  const parser = new PostalMime.default();
  const email = await parser.parse(await new Response(message.raw).arrayBuffer());

  // Filter spam keywords
  const spamKeywords = ['viagra', 'lottery', 'prince'];
  const isSpam = spamKeywords.some(keyword =>
    email.subject.toLowerCase().includes(keyword) ||
    email.text.toLowerCase().includes(keyword)
  );

  if (isSpam) {
    message.setReject('Spam detected');
    return;
  }

  await message.forward('you@gmail.com');
}
```

---

## When to Load References

### Load `references/setup-guide.md` when:
- First-time Email Routing setup
- Configuring MX records
- Setting up email workers
- Configuring send email binding
- Complete walkthrough needed

---

## Using Bundled Resources

**References** (`references/`):
- `setup-guide.md` - Complete setup walkthrough (enabling routing, email workers, send email)
- `common-errors.md` - All 8 documented errors with solutions and prevention
- `dns-setup.md` - MX records, SPF, DKIM configuration guide
- `local-development.md` - Local testing and development patterns

**Templates** (`templates/`):
- `receive-basic.ts` - Basic email receiving worker
- `receive-allowlist.ts` - Email allowlist implementation
- `receive-blocklist.ts` - Email blocklist implementation
- `receive-reply.ts` - Auto-reply email worker
- `send-basic.ts` - Basic send email example
- `send-notification.ts` - Notification email pattern
- `wrangler-email.jsonc` - Wrangler configuration for email routing

---

## Official Documentation

- **Email Routing**: https://developers.cloudflare.com/email-routing/
- **Email Workers**: https://developers.cloudflare.com/email-routing/email-workers/
- **Send Email**: https://developers.cloudflare.com/email-routing/email-workers/send-email-workers/

---

**Questions? Issues?**

1. Check `references/setup-guide.md` for complete setup
2. Verify node_compat: true in wrangler.jsonc
3. Confirm destination addresses verified
4. Check logs for errors


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