Email API

Seamless email integration with excellent deliverability

Start sending in minutes with Postmark’s powerful email API.

47 man developer with code

Robust libraries for fast and easy integration

Integrating email into your product doesn’t have to be a pain. With our RESTful email APIs and robust libraries in pretty much every programming language, integrating email is fast and easy—whether you’re sending transactional or broadcast/bulk email.

# Send an email with curl
# Copy and paste this into terminal

curl "https://api.postmarkapp.com/email" \
  -X POST \
  -H "Accept: application/json" \
  -H "Content-Type: application/json" \
  -H "X-Postmark-Server-Token: server token" \
  -d '{
  "From": "sender@example.com",
  "To": "receiver@example.com",
  "Subject": "Postmark test",
  "TextBody": "Hello dear Postmark user.",
  "HtmlBody": "<html><body><strong>Hello</strong> dear Postmark user.</body></html>",
  "MessageStream": "outbound"
}'
# Send an email with the Postmark Rails Gem
# Learn more -> https://postmarkapp.com/developer/integration/official-libraries#rails-gem

# Add this to your gemfile
gem 'postmark-rails'

# Add this to your config/application.rb file:
config.action_mailer.delivery_method = :postmark
config.action_mailer.postmark_settings = { :api_token => "POSTMARK_API_TEST" }

# Send the email
class TestMailer < ActionMailer::Base
  def hello
    mail(
      :subject => 'Hello from Postmark',
      :to  => 'receiver@example.com',
      :from => 'sender@example.com',
      :html_body => '<strong>Hello</strong> dear Postmark user.',
      :track_opens => 'true'
    )
  end
end
# Send an email with the Postmark Ruby Gem
# Learn more -> https://postmarkapp.com/developer/integration/official-libraries#ruby-gem

# Add the Postmark Ruby Gem to your Gemfile
gem 'postmark'

# Require gem
require 'postmark'

# Create an instance of Postmark::ApiClient
client = Postmark::ApiClient.new('POSTMARK_API_TEST')

# Example request
client.deliver(
  from: 'sender@example.com',
  to: 'receiver@example.com',
  subject: 'Hello from Postmark',
  html_body: '<strong>Hello</strong> dear Postmark user.',
  track_opens: true
)
// Send an email with the Postmark .NET library
// Learn more -> https://postmarkapp.com/developer/integration/official-libraries#dot-net

// Install with NuGet
PM> Install-Package Postmark

// Import
using PostmarkDotNet;

// Example request
PostmarkMessage message = new PostmarkMessage {
    From = "sender@example.com",
    To = "receiver@example.com",
    Subject = "Hello from Postmark",
    HtmlBody = "<strong>Hello</strong> dear Postmark user.",
    TextBody = "Hello dear postmark user.",
    ReplyTo = "reply@example.com",
    TrackOpens = true,
    Headers = new NameValueCollection {{ "CUSTOM-HEADER", "value" }}
};

PostmarkClient client = new PostmarkClient("POSTMARK_API_TEST");

PostmarkResponse response = client.SendMessage(message);

if(response.Status != PostmarkStatus.Success) {
    Console.WriteLine("Response was: " + response.Message);
}
// Send an email with the Postmark-PHP library
// Learn more -> https://postmarkapp.com/developer/integration/official-libraries#php

// Install with composer
composer require wildbit/postmark-php

// Import
use Postmark\PostmarkClient;

// Example request
$client = new PostmarkClient("server token");

$sendResult = $client->sendEmail(
  "sender@example.com",
  "receiver@example.com",
  "Hello from Postmark!",
  "This is just a friendly 'hello' from your friends at Postmark."
);
// Send an email with the Postmark.js library
// Learn more -> https://postmarkapp.com/developer/integration/official-libraries#node-js

// Install with npm
npm install postmark --save

// Require
var postmark = require("postmark");

// Example request
var client = new postmark.ServerClient("server token");

client.sendEmail({
    "From": "sender@example.com",
    "To": "receiver@example.com",
    "Subject": "Test",
    "TextBody": "Hello from Postmark!"
});
# Install with: pip install postmark-python
# Then import as: postmark (the PyPI package and import names differ)
import asyncio
import os

import postmark

async def main():
    async with postmark.ServerClient(os.environ["POSTMARK_SERVER_TOKEN"]) as client:
        response = await client.outbound.send({
            "sender": "sender@example.com",
            "to": "recipient@example.com",
            "subject": "Hello from Postmark",
            "text_body": "Sent with the Postmark Python SDK.",
        })
        print(f"Sent: {response.message_id}")

asyncio.run(main())

Switching to Postmark?

Check out our handy migration guides

Do more than just send email

With our flexible email APIs you can manage domains and templates, retrieve stats, process inbound email, and so much more. For many email providers, APIs are an afterthought. Here at Postmark, we think API-first.

Stellar deliverability

We believe that every customer deserves great delivery. It’s just part of the deal when you use Postmark.

Developer-friendly documentation

Learn how to get the most out of Postmark with our easy-to-follow getting started guides.

Top-notch support as a standard

You will never be charged extra for great support. We’re always here to help whether it’s through email, live-chat, or a 1-on-1 call.

Actionable email insights

Whether it’s measuring email opens and clicks or gathering delivery insights, Postmark’s real-time analytics have got you covered.

Secure and GDPR friendly

We value your trust and work hard to protect your information—and that of your customers. Postmark is GDPR compliant.

Email authentication made easy

We guide you through setting up DMARC and SPF to help protect your domain from spoofing.

Why Our Customers Love Us ❤️

It was incredibly easy to setup Postmark. In under 10 minutes I had the first test working and rolling it out to production was just as easy.

Dave Teare

Dave Teare

Founder at 1Password

Get Started Free Today!

Join thousands of businesses who trust Postmark for their email needs. 
Sign up now and see the difference!