Production checklist

1. Verify your sending domain

   Add all setup records shown in the dashboard and wait until each one is verified. If lm1 and lm2 are shown, configure both.

   Verified domain DNS records and success state.

2. Create Project API tokens per integration

   Create a separate Project API token for each app, worker, or environment. Store each token as LETTERMINT_PROJECT_TOKEN. Add an IP allowlist for integrations that send from stable outbound IP addresses.

   Project API token list showing token names, restriction, last changed, last used, and last IP.

3. Confirm the default outbound route

   New projects can create transactional and broadcast routes. Confirm which transactional or broadcast route is the default before omitting route from send requests.

4. Send test-address scenarios

   Use Lettermint test addresses to simulate deliveries, soft bounces, hard bounces, and spam complaints without affecting sender reputation.

5. Use idempotency for retried sends

   Add an Idempotency-Key for important transactional sends. Keys are scoped per project and valid for 24 hours.

6. Set suppression policy

   Decide when to use team, project, and route-level suppressions. Make sure support and compliance teams know spam complaint suppressions cannot be removed through normal self-service.

7. Configure webhooks and signature verification

   Subscribe each route to the events your app needs, store the webhook signing secret, and verify signatures before processing payloads.

   Webhook delivery detail showing attempts, response status, and retry action.

8. Choose a TLS delivery policy

   Keep opportunistic TLS for maximum compatibility, or enforce TLS on routes where delivery must fail rather than continue without encryption. Test your webhook handling for enforced_tls_failed before enabling enforced TLS in production.

9. Review tracking and privacy choices

   Enable open and click tracking only where appropriate. For critical security emails, consider leaving tracking disabled.

10. Set billing and spend controls

Review your plan, monthly included email volume, and spend limit behavior before production volume ramps up.

11. Monitor delivery

    Use Email Activity, webhooks, and Team API message endpoints to watch delivery, bounces, complaints, and delivery insights.