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Specify recipients

Email Service lets you specify recipients in several ways — multiple recipients, CC and BCC, and named addresses — using the Workers binding, the REST API, or SMTP. The combined number of addresses across to, cc, and bcc must not exceed 50. See Limits.

Multiple recipients

const response = await env.EMAIL.send({
	to: ["user1@example.com", "user2@example.com", "user3@example.com"],
	from: { email: "newsletter@yourdomain.com", name: "Newsletter Team" },
	subject: "Monthly Newsletter",
	html: "<h1>This month's updates</h1>",
	text: "This month's updates",
});
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": ["user1@example.com", "user2@example.com"],
    "from": { "address": "newsletter@yourdomain.com", "name": "Newsletter Team" },
    "subject": "Monthly Newsletter",
    "html": "<h1>This month'\''s updates</h1>",
    "text": "This month'\''s updates"
  }'

List every recipient in the To header and pass one --mail-rcpt flag per address.

cat > mail.txt <<EOF
From: Newsletter Team <newsletter@yourdomain.com>
To: user1@example.com, user2@example.com
Subject: Monthly Newsletter

This month's updates
EOF

curl --ssl-reqd \
  --url "smtps://smtp.mx.cloudflare.net:465" \
  --user "api_token:<API_TOKEN>" \
  --mail-from "newsletter@yourdomain.com" \
  --mail-rcpt "user1@example.com" \
  --mail-rcpt "user2@example.com" \
  --upload-file mail.txt

CC and BCC

const response = await env.EMAIL.send({
	to: "customer@example.com",
	cc: ["manager@example.com"],
	bcc: ["archive@example.com"],
	from: "orders@yourdomain.com",
	replyTo: "support@yourdomain.com",
	subject: "Order Confirmation #12345",
	html: "<h1>Your order is confirmed</h1>",
	text: "Your order is confirmed",
});
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": "customer@example.com",
    "cc": ["manager@example.com"],
    "bcc": ["archive@example.com"],
    "from": "orders@yourdomain.com",
    "reply_to": "support@yourdomain.com",
    "subject": "Order Confirmation #12345",
    "html": "<h1>Your order is confirmed</h1>",
    "text": "Your order is confirmed"
  }'

Add a Cc header for CC recipients. BCC recipients are added as --mail-rcpt flags but omitted from the headers.

cat > mail.txt <<EOF
From: orders@yourdomain.com
To: customer@example.com
Cc: manager@example.com
Reply-To: support@yourdomain.com
Subject: Order Confirmation #12345

Your order is confirmed
EOF

curl --ssl-reqd \
  --url "smtps://smtp.mx.cloudflare.net:465" \
  --user "api_token:<API_TOKEN>" \
  --mail-from "orders@yourdomain.com" \
  --mail-rcpt "customer@example.com" \
  --mail-rcpt "manager@example.com" \
  --mail-rcpt "archive@example.com" \
  --upload-file mail.txt

Named recipients

Provide a display name alongside the address for the sender and recipients.

const response = await env.EMAIL.send({
	to: { email: "jane@example.com", name: "Jane Doe" },
	from: { email: "support@yourdomain.com", name: "Support Team" },
	subject: "Welcome!",
	html: "<h1>Thanks for joining!</h1>",
	text: "Thanks for joining!",
});
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": { "address": "jane@example.com", "name": "Jane Doe" },
    "from": { "address": "support@yourdomain.com", "name": "Support Team" },
    "subject": "Welcome!",
    "html": "<h1>Thanks for joining!</h1>",
    "text": "Thanks for joining!"
  }'

Use the Display Name <address> form in the From and To headers.

cat > mail.txt <<EOF
From: Support Team <support@yourdomain.com>
To: Jane Doe <jane@example.com>
Subject: Welcome!

Thanks for joining!
EOF

curl --ssl-reqd \
  --url "smtps://smtp.mx.cloudflare.net:465" \
  --user "api_token:<API_TOKEN>" \
  --mail-from "support@yourdomain.com" \
  --mail-rcpt "jane@example.com" \
  --upload-file mail.txt

Mixed plain and named recipients

Combine plain addresses and named addresses in the same to field.

const response = await env.EMAIL.send({
	to: ["plain@example.com", { email: "jane@example.com", name: "Jane Doe" }],
	from: "support@yourdomain.com",
	subject: "Team update",
	html: "<h1>Monthly update</h1>",
	text: "Monthly update",
});
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": [
      "plain@example.com",
      { "address": "jane@example.com", "name": "Jane Doe" }
    ],
    "from": "support@yourdomain.com",
    "subject": "Team update",
    "html": "<h1>Monthly update</h1>",
    "text": "Monthly update"
  }'
cat > mail.txt <<EOF
From: support@yourdomain.com
To: plain@example.com, Jane Doe <jane@example.com>
Subject: Team update

Monthly update
EOF

curl --ssl-reqd \
  --url "smtps://smtp.mx.cloudflare.net:465" \
  --user "api_token:<API_TOKEN>" \
  --mail-from "support@yourdomain.com" \
  --mail-rcpt "plain@example.com" \
  --mail-rcpt "jane@example.com" \
  --upload-file mail.txt

Next steps