Get started

Production checklist

Use this checklist before switching real traffic to Lettermint.

Verify your sending domain

Add all setup records shown in the dashboard and wait until each one is verified. If lm1._domainkey and lm2._domainkey are shown, configure both.
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.
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.
Send test-address scenarios

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

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

Select all projects, one or more projects, or one or more routes. Subscribe to the events your app needs, store the signing secret, and verify signatures before you process payloads.
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.
Review tracking and privacy choices

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