In simple English
Sending emails to your users normally requires paying a third-party company per message or contact. Plunk lets you run your own email server on your hardware. You can send transactional alerts, newsletters, and automated sequences from your own domain. It costs nothing in software fees, but you must handle server setup and maintenance yourself. If you run a web app and want to stop paying expensive monthly email bills, this tool solves that problem.
What it is
Plunk is a self-hosted email platform built with TypeScript (a programming language that adds safety rules to JavaScript). It combines transactional sending, marketing campaigns, contact management, and workflow automation into a single dashboard.
What it is good for
Solo builders who want to cut monthly messaging costs and keep all customer contact data on their own server.
- Handles transactional messages, newsletters, and automated drip campaigns in one place.
- Includes contact management with custom fields and real-time open and click analytics.
- Supports inbound email processing so you can receive and route incoming messages.
- Setup requires configuring Docker (a way to run a program inside its own sealed box, so it cannot break anything else on your server) and managing DNS records like SPF and DKIM.
- Uses AGPL-3.0 (a strict open-source licence that forces you to share your code if you modify it and offer it as a service), which requires care if you build commercial products on top of it.
- Requires your own SMTP relay or email provider to deliver messages to the outside world reliably.
Paid email delivery services like SendGrid, Resend, or Mailgun
PostgreSQL database and a mail server relay
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docker pull ghcr.io/useplunk/plunk:latest