Postmark

1. API overview

   API basics, server and account tokens and conventions.

2. Sending email

   Sending email through the HTTP API.

3. Message streams API

   Message streams that separate transactional and broadcast email.

4. Templates API

   Templates and layouts with template models.

5. Webhooks

   Webhooks for delivery, bounce, open, click and spam events.

6. Inbound

   Inbound email processing and webhooks.

7. Bounce handling

   The bounce API, bounce types and reactivating addresses.

8. SMTP

   Sending through SMTP.

9. Tracking

   Open and link tracking.

10. Errors

    API error codes and how to handle them.

Each section links to the official page. Titles and summaries by Extra Credit; the docs belong to their authors.