Postmark

Postmark Transactional Email API Skill

Overview

Postmark specializes in lightning-fast transactional email delivery with industry-leading inbox placement, detailed bounce classification, and templating.

Installation

npm install postmark

Setup & Sending Emails

import { ServerClient } from 'postmark';

const client = new ServerClient(process.env.POSTMARK_SERVER_API_TOKEN!);

// Send single transactional email
await client.sendEmail({
  From: 'support@myverifieddomain.com',
  To: 'user@example.com',
  Subject: 'Password Reset Request',
  HtmlBody: '<p>Click <a href="https://example.com/reset">here</a> to reset your password.</p>',
  TextBody: 'Visit https://example.com/reset to reset your password.',
  MessageStream: 'outbound',
});

Sending via Postmark Template

await client.sendEmailWithTemplate({
  From: 'notifications@myverifieddomain.com',
  To: 'customer@example.com',
  TemplateAlias: 'welcome-email',
  TemplateModel: {
    name: 'Alex',
    action_url: 'https://myverifieddomain.com/dashboard',
    product_name: 'Awesome Platform',
  },
});

AI Pitfalls & Anti-Hallucination Guidelines

• Token Confusion: Postmark has Account API Tokens (admin operations) and Server API Tokens (sending emails). Do not send emails using Account Tokens.
• Sender Signatures: Attempting to send from an unverified From address will return an HTTP 422 error.

Production Verification Checklist

• SPF, DKIM, and DMARC DNS records configured on sending domain
• Inbound webhooks verified with IP filtering or basic auth
• Bounce webhook configured to suppress inactive email addresses

Last Verified: 2026-07-03