Quickstart guide

It’s free to sign up and to send up to 300 emails per month, with a BAA included.

Note:If you send more than 300 emails in one month, you will be automatically moved to the appropriate pricing tier and billed the annual cost.

Add and verify your domain

Once you have a Paubox account, go to the Settings > Domains page and add the domain you’ll be sending from.Paubox verifies domain ownership via your domain’s SPF record. Paubox will display the SPF value to add at your DNS provider (e.g., Route 53, Cloudflare, GoDaddy). Add or update the SPF record in your domain’s DNS, then return to the Settings > Domains page and click Verify.

Tip:Most DNS providers propagate DNS changes within a few minutes, but allow up to 48 hours. If verification fails immediately, wait a few minutes and try again.

Generate an API key

From the Settings > API Keys page, click on the domain you would like to generate an API key for, then press the Add API Key button. Give the key a description and a new key will be generated upon submission.Make sure you save your key because if you lose it you will have to generate a new one.All Email API requests use the same base URL:

https://api.paubox.com/v1/email

You will use this base URL in every API request.

Send your first email

Use the following curl command to send a test email. Replace YOUR_API_KEY and the from address with your actual values. The from address must match your verified domain.

curl --request POST \
  --url https://api.paubox.com/v1/email/messages \
  --header 'Authorization: Bearer YOUR_API_KEY' \
  --header 'Content-Type: application/json' \
  --data '{
    "data": {
      "message": {
        "recipients": ["recipient@example.com"],
        "headers": {
          "subject": "Hello from Paubox",
          "from": "sender@yourdomain.com"
        },
        "content": {
          "text/plain": "Hello world",
          "text/html": "<html><body><h1>Hello world</h1></body></html>"
        }
      }
    }
  }'

What success looks like:A 200 OK response confirms your message was accepted for delivery:

{
  "sourceTrackingId": "3d38ab13-0af8-4028-bd45-52e882e0d584",
  "data": "Service OK"
}

Save the sourceTrackingId; you can use it to check delivery status later.

Integrate via SDK

Official SDKs handle authentication and request formatting for you. Choose your language:

Prefer the terminal? See the CLI quickstart to send email without writing code.

Next steps

Track message status

Check delivery status using a sourceTrackingId

Send attachments

Add files to your messages via the REST API

MCP server

Use Paubox from AI agents and editors via MCP

Introduction

General information

⌘I

Get started

Email API

Migrate to Paubox

Marketing API

MCP Server

SDKs

CLI

Forms API

Next steps

Track message status

Send attachments

MCP server

​Next steps

Track message status

Send attachments

MCP server

Next steps