email-best-practices

To stop transactional emails going to spam in Gmail, implement SPF, DKIM, and DMARC authentication, verify your DNS records, add a List-Unsubscribe header, and set up webhook-driven suppression lists based on bounce and complaint events.

The best way to implement SPF, DKIM, and DMARC for email deliverability is to follow a phased rollout plan that updates DNS records, authenticates sending domains, and monitors aggregate reports to enforce DMARC policies while warming up your sending IP.

Manage email list hygiene by processing webhook events to automatically deduplicate bounces and complaints, then update your suppression lists and retention rules based on ongoing delivery outcomes to maintain sender reputation.

GDPR and CASL compliance requires explicit consent and verifiable records, making double opt-in a reliable mechanism to validate email addresses and document subscriber permission for both marketing and transactional use cases.

Idempotency keys and retry backoff strategies ensure production-grade email sending reliability by preventing duplicate message delivery during network timeouts and safely re-queuing failed requests without exceeding rate limits.

You should separate sending infrastructure for marketing versus transactional emails to isolate sender reputation, preventing marketing complaint rates from negatively impacting the deliverability of critical transactional messages.