postkit
Concepts

Concepts

Understand how Postkit works under the hood

Deep-dive explanations of the systems and standards behind transactional email delivery.

These pages explain the why behind Postkit's design decisions and the email standards that matter for deliverability.

  • Email Delivery Pipeline -- How your emails travel from API request to inbox, including queuing, SMTP handoff, and event tracking.
  • DKIM, SPF & DMARC -- The email authentication standards that prevent spoofing and improve deliverability.
  • Rate Limits & Quotas -- How API rate limiting works, sending quotas, and cursor-based pagination.
  • EU Data Residency -- How Postkit ensures all data stays within the European Union for GDPR compliance.
  • Idempotency -- Safely retry API requests without sending duplicate emails.
  • Error Handling -- Understanding API error types, response formats, and best practices for handling failures.