Transactional email made easy

Power your app's communication with a fast and reliable transactional email service.

A transactional email service you can count on

Do your transactional emails take forever to arrive (or never make it to the inbox), leaving your customers frustrated? Not with Postmark. You can count on us to get your emails delivered fast and reliably—so you can go back to building great products.

Postmark transactional email powers:

  • Password reset emails

    Password reset emails

  • Receipt and invoice emails

    Receipt and invoice emails

  • Trial expiration emails

    Trial expiration emails

  • User invitation emails

    User invitation emails

  • Notification emails

    Notification emails

  • Welcome emails

    Welcome emails

Easy integration via API or SMTP

Get seamless and lightning fast email delivery using our versatile API or SMTP integration. Quickly implement email in your app using our robust libraries, and access great customer support whenever you need it.

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

  curl "" \
    -X POST \
    -H "Accept: application/json" \
    -H "Content-Type: application/json" \
    -H "X-Postmark-Server-Token: server token" \
    -d '{
    "From": "",
    "To": "",
    "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 ->

  # 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
        :subject => 'Hello from Postmark',
        :to  => '',
        :from => '',
        :html_body => '<strong>Hello</strong> dear Postmark user.',
        :track_opens => 'true'
# Send an email with the Postmark Ruby Gem
  # Learn more ->

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

  # Require gem
  require 'postmark'

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

  # Example request
    from: '',
    to: '',
    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 ->

  // Install with NuGet
  PM> Install-Package Postmark

  // Import
  using PostmarkDotNet;

  // Example request
  PostmarkMessage message = new PostmarkMessage {
      From = "",
      To = "",
      Subject = "Hello from Postmark",
      HtmlBody = "<strong>Hello</strong> dear Postmark user.",
      TextBody = "Hello dear postmark user.",
      ReplyTo = "",
      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 ->

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

  // Import
  use Postmark\PostmarkClient;

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

  $sendResult = $client->sendEmail(
    "Hello from Postmark!",
    "This is just a friendly 'hello' from your friends at Postmark."
// Send an email with the Postmark.js library
  // Learn more ->

  // Install with npm
  npm install postmark --save

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

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

      "From": "",
      "To": "",
      "Subject": "Test",
      "TextBody": "Hello from Postmark!"

Why choose Postmark?

  • Unmatched deliverability

    Stellar deliverability

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

  • Developer-friendly documentation

    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

    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.

  • Globally distributed SMTP service

    Globally distributed SMTP service

    We maintain endpoints in several AWS Regions around the world. We route to the closest endpoints to your servers for the fastest response times possible, resulting in very low latency.

  • Secure and GDPR friendly

    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

    Email authentication made easy

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

Postmark ❤️

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

Ready to get started?

Join thousands of businesses that already trust their email delivery to Postmark.