Email Deliverability Checklist

Use this checklist before launch and during ongoing operations. Consistency across these items usually matters more than any single deliverability trick.

Domain and DNS

  • Verify SPF and DKIM for every sending domain.
  • Send from the same domain users expect for your product.
  • Test DNS propagation before moving high volume traffic.

Recipient quality

  • Only send to users who requested or expect the message.
  • Suppress hard bounces and repeated soft bounces.
  • Protect against invalid addresses at signup and checkout.

Message quality

  • Use specific subject lines that match the message intent.
  • Provide both HTML and plain-text content when possible.
  • Avoid URL shorteners and suspicious link patterns.

Event processing

  • Consume webhook events for deliveries, bounces, and complaints.
  • Make webhook handlers idempotent to handle retries safely.
  • Feed complaint and bounce data into suppression lists.

Operational monitoring

  • Track complaint and bounce percentages by domain.
  • Alert on unusual spikes in failures or delays.
  • Review account-level metrics weekly and after major launches.

For implementation details, open the API docs and pair this checklist with the language quickstart guides.