Postmark is a transactional email API known for fast delivery and strong deliverability — receipts, password resets, alerts and other app-triggered email. It keeps transactional and broadcast streams separate so your important mail isn't slowed by bulk sends. Here's the pricing, the free test tier, and how to get a token.
| Plan | Price | Emails |
|---|---|---|
| Developer free tier | $0 | 100 / mo (testing) + free DMARC |
| 10k | from ~$15/mo | 10,000 / mo |
| 50k | from ~$55/mo | 50,000 / mo |
| 125k | from ~$115/mo | 125,000 / mo |
| Higher volume | custom | 300k+, lower per-email rate |
Postmark's free Developer tier sends 100 emails per month — enough to wire up and test your integration, but not for production. There's no perpetual large free tier like Resend's 3,000/mo, so Postmark is best thought of as a paid, deliverability-first service. The upside is free DMARC monitoring for your domain, which is genuinely useful for protecting your sending reputation even before you go paid.
1. Sign up at postmarkapp.com.
2. Create a Server (a logical sending environment — e.g. one for production, one for staging).
3. Verify your domain or sender signature by adding the SPF, DKIM and (recommended) DMARC DNS records Postmark shows you.
4. Open the server's API Tokens tab and copy the Server API Token — this is the token you send in the X-Postmark-Server-Token header.
Send a test email:
Amazon SES is the cheapest at scale (~$0.10 per 1,000 emails) but bare-bones to set up. Resend (see our Resend guide) has a far more generous 3,000/mo free tier and great developer experience. SendGrid (SendGrid guide) adds marketing-email features, and Mailgun (Mailgun guide) is a solid mid-market option with EU regions. Postmark's edge is transactional deliverability and speed. Compare them all for your volume with the email API cost calculator. For SMS instead of email, see Twilio.
Yes, but small — 100 emails/month for testing, plus free DMARC monitoring. Production sending starts around $15/mo for 10,000 emails.
Sign up, create a Server, verify your domain via DNS (SPF + DKIM + DMARC), then copy the Server API Token from the API Tokens tab and send it in the X-Postmark-Server-Token header.
For pure volume at scale, Amazon SES beats both. Between the two, SendGrid has a small ongoing free tier and more marketing features; Postmark charges from ~$15/mo but is prized for fast, reliable transactional delivery. Compare exact numbers in the email cost calculator.
Postmark separates outbound mail into streams — typically a transactional stream and a broadcast/marketing stream — so bulk sends never delay time-sensitive transactional email. You set the stream in the MessageStream field of the API call.
Not affiliated with Postmark. Prices are reference estimates — always verify on the official pricing page.