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.