Reliable transactional email for self-hosted n8n workflows with zero expiring OAuth tokens

{
  "nodes": [
    {
      "parameters": {
        "method": "POST",
        "url": "https://api.sadasend.com/emails",
        "authentication": "genericCredentialType",
        "genericAuthType": "httpHeaderAuth",
        "sendHeaders": true,
        "headerParameters": {
          "parameters": [
            {
              "name": "Authorization",
              "value": "Bearer YOUR_SADASEND_API_KEY"
            },
            {
              "name": "Content-Type",
              "value": "application/json"
            }
          ]
        },
        "sendBody": true,
        "specifyBody": "json",
        "jsonBody": "={\n  \"from\": \"notifications@yourdomain.com\",\n  \"to\": \"{{ $json.customer_email }}\",\n  \"subject\": \"Your Order #{{ $json.order_id }} is Confirmed\",\n  \"html\": \"<h2>Hello {{ $json.customer_name }},</h2><p>Your order is on its way!</p>\"\n}"
      },
      "name": "Send Email via SadaSend",
      "type": "n8n-nodes-base.httpRequest",
      "typeVersion": 4.2,
      "position": [460, 300]
    }
  ]
}