Send emails

If you are building on Cloudflare Workers, you can use the Workers binding for native email sending. Start by creating a new Worker project.

1. Create a new Worker project:

   npmyarnpnpm

   npm create cloudflare@latest -- email-service-tutorial

   When prompted, select "Hello World" Worker as the template.

2. Add the email binding to your Wrangler configuration file:

   {
   	"send_email": [
   		{
   			"name": "EMAIL",
   			"remote": true,
   		},
   	],
   }

   [[send_email]]
   name = "EMAIL"
   remote = true

3. Create your Worker code in src/index.ts:

   // Configuration - Update these values
   const YOUR_DOMAIN = "yourdomain.com"; // Replace with your verified domain
   const RECIPIENT_EMAIL = "[email protected]"; // Replace with your email to receive test emails
   
   export default {
   	async fetch(request: Request, env: Env): Promise<Response> {
   		// Send a welcome email
   		const response = await env.EMAIL.send({
   			to: RECIPIENT_EMAIL,
   			from: `welcome@${YOUR_DOMAIN}`,
   			subject: "Welcome to our service!",
   			html: "<h1>Welcome!</h1><p>Thanks for signing up.</p>",
   			text: "Welcome! Thanks for signing up.",
   		});
   
   		return new Response(`Email sent: ${response.messageId}`);
   	},
   } satisfies ExportedHandler<Env>;

4. Use npx wrangler dev to develop your Worker project and send emails. This runs your code locally while connecting to Cloudflare Email Service (using remote bindings).

   npx wrangler dev
   # ⎔ Starting remote preview...
   # Total Upload: 24.96 KiB / gzip: 6.17 KiB
   # [wrangler:info] Ready on http://localhost:8787

5. Deploy your Worker:

   npm run deploy

After deploying, test that your Worker can send emails:

1. Visit your Worker URL in a browser (shown in the deploy output, for example: https://email-service-tutorial.<your-subdomain>.workers.dev).
2. You should see a response like Email sent: <message-id>.
3. Check the inbox for the email address you specified in RECIPIENT_EMAIL. If you do not see the email, check your spam folder.

Send an email with a single curl command. Replace {account_id} with your Cloudflare account ID and <API_TOKEN> with an API token.

curl "https://api.cloudflare.com/client/v4/accounts/{account_id}/email/sending/send" \
  --header "Authorization: Bearer <API_TOKEN>" \
  --header "Content-Type: application/json" \
  --data '{
    "to": "[email protected]",
    "from": "[email protected]",
    "subject": "Welcome to our service!",
    "html": "<h1>Welcome!</h1><p>Thanks for signing up.</p>",
    "text": "Welcome! Thanks for signing up."
  }'

A successful response includes the delivery status for each recipient:

{
	"success": true,
	"errors": [],
	"messages": [],
	"result": {
		"delivered": ["[email protected]"],
		"permanent_bounces": [],
		"queued": []
	}
}

For more details, see the REST API reference.

Send an email with a single curl command. Replace <API_TOKEN> with a Cloudflare API token that has the Email Sending: Edit permission, and replace the --mail-from and --mail-rcpt addresses with your own.

cat > mail.txt <<EOF
From: [email protected]
To: [email protected]
Subject: Welcome to our service!

Thanks for signing up.
EOF

curl --ssl-reqd \
  --url "smtps://smtp.mx.cloudflare.net:465" \
  --user "api_token:<API_TOKEN>" \
  --mail-from "[email protected]" \
  --mail-rcpt "[email protected]" \
  --upload-file mail.txt

The sender domain ([email protected]) must be onboarded for Email Sending on the account that owns the API token.

For connection details, authentication, response codes, and language-specific examples, see the SMTP reference.