Postmark

Stop worrying if your emails made it to the inbox, and get back to focusing on what matters, building great products.

Postmark is transactional email with deliverability as the product: a sending API separated from broadcast streams, 45-day full content history, delivery webhooks, and support staff who respond to deliverability questions with actual analysis rather than a template.

Why founders use it: transactional email is the highest-stakes, lowest-glamour channel, password resets, receipts, alerts, and the difference between providers shows up exactly when something breaks. Postmark's separation of transactional and broadcast reputation means the password reset never competes with the newsletter for inbox placement. The activity history makes "did the user get it" a lookup instead of a dispute.

A realistic setup: streams separating transactional from broadcast, templates with live previews, inbound parsing for replies, webhooks writing bounces and spam complaints into monitoring, and DMARC aligned from day one.

Trade-offs: per-message pricing sits above raw SMTP providers, broadcast volume gets expensive, and the feature set is deliberately narrow. Compare with Resend for DX, Mailgun for inbound tooling, and Loops when marketing email grows into its own need.