Quickstart

This guide walks you through sending your first email with the RelayPost REST API.

Note

The RelayPost dashboard uses a separate internal GraphQL API. This documentation covers the public REST API for external integrations.

Prerequisites

• A RelayPost account — sign up free
• A domain you control (for production sending)

1. Create an organization

After signing up, you’ll be prompted to create an organization. This is your workspace — all API keys, domains, and emails are scoped to it.

2. Generate an API key

Go to Settings → API Keys and create a new key. Copy it immediately — it’s only shown once.

Your key looks like: rp_live_aBcDeFgHiJkLmNoPqRsT...

3. Send your first email

cURL

curl -X POST https://relaypost.dev/api/v1/emails/send \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "from": { "email": "[email protected]", "name": "Your App" },
    "to": [{ "email": "[email protected]" }],
    "subject": "Hello from RelayPost",
    "html": "<h1>It works!</h1><p>Your email delivery is set up.</p>"
  }'

JavaScript

const response = await fetch("https://relaypost.dev/api/v1/emails/send", {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
    Authorization: "Bearer YOUR_API_KEY",
  },
  body: JSON.stringify({
    from: { email: "[email protected]", name: "Your App" },
    to: [{ email: "[email protected]" }],
    subject: "Hello from RelayPost",
    html: "<h1>It works!</h1><p>Your email delivery is set up.</p>",
  }),
});

const result = await response.json();
console.log(result.data.message_id);

Python

import requests

response = requests.post(
    "https://relaypost.dev/api/v1/emails/send",
    headers={
        "Content-Type": "application/json",
        "Authorization": "Bearer YOUR_API_KEY",
    },
    json={
        "from": {"email": "[email protected]", "name": "Your App"},
        "to": [{"email": "[email protected]"}],
        "subject": "Hello from RelayPost",
        "html": "<h1>It works!</h1><p>Your email delivery is set up.</p>",
    },
)

result = response.json()
print(result["data"]["message_id"])

4. Check the response

A successful send returns:

{
  "data": {
    "message_id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
    "status": "queued",
    "queued_at": "2025-01-15T10:30:00.000Z"
  }
}

Tip

For production sending, verify your domain first. Unverified domains may have lower deliverability.

What’s next

• Verify your domain for better inbox placement
• Set up webhooks to track delivery events
• Create templates for reusable email layouts
• Send via SMTP if your app uses SMTP