email-and-templatinglisted

# Email and templating Scope: email-and-templating — transactional email provider selection, react-email/MJML templating, and SPF/DKIM/DMARC deliverability basics. It does not own marketing/broadcast email strategy, unsubscribe/consent policy (`feature-legal-risk-checklist`'s "Email / messaging" risk area owns the CAN-SPAM-style compliance framing), or general webhook idempotency beyond what a provider's delivery-event webhook needs (`error-handling-and-resilience` owns that mechanic generally). ## 1. Provider choice — Resend, Postmark, SES All three are transactional (not bulk/marketing) email APIs; pick by what the task actually needs, not by default habit: - **Resend** — optimizes for developer experience: a modern TypeScript SDK, first-class **react-email** integration (templates are React components, rendered server-side), and a generous free/low-volume tier. Under the hood Resend routes sends through Amazon SES infrastructure rather than running its own — so it inherits SES's deliverability floor while adding DX on top. Good default for a new project already on React/Node that wants templates-as-components with minimal setup. - **Postmark** — optimizes for deliverability and transactional-specific operational tooling: separate **message streams** for transactional vs. broadcast mail (so a bulk send never risks the transactional stream's reputation), detailed bounce/spam-complaint tracking, and fast, reliable delivery. Reach for it when deliverabi