Postmark

Overview

Integration

User guide

API reference

Webhooks

Introduction

Postmark helps deliver and track transactional emails for web applications. In a nutshell, the service replaces SMTP (or Sendmail) with a far more reliable, scalable and care-free environment. In addition, you can track statistics such as number of emails sent or processed, opens, bounces and spam complaints.

Things you should know

  • Postmark is for transactional email only. You may not send newsletters, announcements, or any other bulk email. If you’re uncertain if your email qualifies as “transactional”, you can always contact support and we’ll review your usage.
  • A confirmed email address is required to start sending. Before you can start sending emails, you will need to verify the email address you send from in our Signatures section.
  • Maximum email size is 10 MB. This includes email content, headers, and attachments. You will receive an error if your emails are too large.
  • Postmark will only accept attachments with specific file types, so please review our list of accepted file types. We also support inline image embedding.
  • The maximum number of recipients for each email is 20, including all To, CC, and BCC recipients. Each recipient counts as a single Postmark credit.

Get started

Integration

Get up and running with an existing Postmark library. This is the fastest way to start sending email with Postmark without having to write your own code.

User guide

User guides provide a detailed walk through on accomplishing specific tasks with Postmark. We recommend this if you’re just getting started.

API reference

Get straight to the details of every HTTP request available through Postmark’s REST API.

Webhooks

Receive instant notifications to your application when specific events occur. Data is posted to your application in a neatly packaged JSON object.