Good email deserves to reach the inbox.

curl -X POST 'https://smtp2u.com/api/emails' \
  -H 'Authorization: Bearer nm_your_api_key' \
  -H 'Content-Type: application/json' \
  -H 'Idempotency-Key: order-123-confirmation' \
  -d '{
    "from": "Acme <hello@yourdomain.com>",
    "to": "customer@example.com",
    "reply_to": "support@yourdomain.com",
    "subject": "Order confirmed",
    "html": "<h1>You are all set!</h1>",
    "attachments": [
      { "filename": "receipt.pdf", "content": "JVBERi0xLjQK…" }
    ]
  }'

# 202 Accepted
# {"id":"2ddfb6e9-d0e7-4433-ad24-172de771eee0","status":"queued"}

const res = await fetch('https://smtp2u.com/api/emails', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer ' + process.env.SMTP2U_KEY,
    'Content-Type': 'application/json',
    'Idempotency-Key': 'order-123-confirmation'
  },
  body: JSON.stringify({
    from: 'Acme <hello@yourdomain.com>',
    to: 'customer@example.com',
    subject: 'Order confirmed',
    html: '<h1>You are all set!</h1>'
  })
});

const { id, status } = await res.json();
// use the id to follow every event of this email

$ch = curl_init('https://smtp2u.com/api/emails');
curl_setopt_array($ch, [
  CURLOPT_POST => true,
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_HTTPHEADER => [
    'Authorization: Bearer ' . getenv('SMTP2U_KEY'),
    'Content-Type: application/json',
  ],
  CURLOPT_POSTFIELDS => json_encode([
    'from' => 'Acme <hello@yourdomain.com>',
    'to' => 'customer@example.com',
    'subject' => 'Order confirmed',
    'html' => '<h1>You are all set!</h1>',
  ]),
]);

$email = json_decode(curl_exec($ch), true);
// $email['id'] identifies the message in every event

import os, requests

r = requests.post(
    'https://smtp2u.com/api/emails',
    headers={'Authorization': 'Bearer ' + os.environ['SMTP2U_KEY']},
    json={
        'from': 'Acme <hello@yourdomain.com>',
        'to': 'customer@example.com',
        'subject': 'Order confirmed',
        'html': '<h1>You are all set!</h1>',
    },
)

print(r.status_code, r.json())
# 202 {'id': '2ddfb6e9-…', 'status': 'queued'}

# Any system that speaks SMTP: CRM, store, website, ERP.

Host       smtp.smtp2u.com
Port       465 (SSL/TLS)  or  587 (STARTTLS)
           alternatives: 2465 and 2587
Username   smtp2u
Password   your API key (nm_…)

# The sender must be on a domain verified in your workspace.
# Attachments up to 10 MB. Everything shows up in Emails, Logs
# and Metrics, with opens and clicks, just like the API.