Two ways in — a step-by-step guide for using UserMails from the dashboard, and a developer reference for the API and the Resend drop-in.
Send from your own domain, host inboxes at you@yourdomain.com, verify lists, watch deliverability, and manage suppressions — all from the dashboard. No code required.
Open the user guide
Quickstart with curl, the Resend drop-in (RESEND_BASE_URL), the verify API, signed webhooks, idempotency, and the full API reference.
Open the developer docs
The white-label tenancy model: organizations, projects, sub-accounts, your domains, branded dashboards — and what white-label deliberately does not change.
Learn the model
API versioning policy and what shipped recently. One current API — additive changes only, breaking changes announced here first.
See what changed
Already using a transactional client? It's a one-line base-URL change — point it at https://api.usermails.com and see the migration guide.