Posta

Posta is a fully open source, MIT licensed, self-hosted transactional email platform enabling you to send and receive emails for your apps via SMTP or an HTTP API. It provides DKIM-signed delivery, inbound mail routing, comprehensive delivery history, bounce handling with automatic suppression, open and click tracking, and signed webhooks. It includes a dashboard for managing organisations, mail servers, domains, and credentials, supporting IP pools and send limits per app. Written in TypeScript on Bun with a Postgres backend, Posta allows you to run your own mail infrastructure without message caps or licensing fees.