Postal - an open source mail delivery platform
A fully featured open source mail delivery platform for incoming & outgoing e-mail
Categories:
Postal is a fully featured open source mail delivery platform for incoming and outgoing e-mail, designed as a self-hosted alternative to services like SendGrid, Mailgun, or Postmark.
🚀 Overview
Postal is a complete and scalable mail server solution that allows you to send and receive emails with full control over your infrastructure. It provides a comprehensive web interface for managing servers, viewing logs, statistics, and queues, making it easy to monitor and troubleshoot email delivery.
The project solves the problem of dependency on proprietary email services that charge per email and limit customization. Instead, Postal enables self-hosting with advanced features like IP reputation management, spam filtering, and webhooks for real-time notifications.
It's built for developers integrating email into web apps, teams needing reliable transactional email, and organizations seeking cost-effective, privacy-focused alternatives to SaaS providers. The motivation behind Postal is to offer a production-ready open-source option that's fully featured and horizontally scalable, putting email infrastructure in users' hands.
✨ Key Features
- Comprehensive web interface with graphs, stats, message search, and queue viewing for easy management and debugging
- Outgoing email via SMTP/HTTP API with DKIM signing, click/open tracking, suppression lists, send limits, IP pools, and tagging
- Incoming email forwarding to HTTP endpoints, SMTP servers, or addresses, plus SpamAssassin/rspamd and ClamAV integration
- Webhooks for real-time delivery events, multi-organization support, development hold mode, DNS monitoring, and customizable retention
🛠 Tech Stack
- Frontend: Haml, SCSS, CoffeeScript (Ruby on Rails asset pipeline)
- Backend: Ruby on Rails
- Database: MariaDB (MySQL compatible), Redis
- Auth: Custom
- Hosting: Docker, Caddy (reverse proxy/SSL), self-hosted
👥 Who Is This For?
This project is useful for:
- Developers who want to integrate scalable email sending/receiving into their apps without SaaS dependencies
- Teams looking for full control over email infrastructure with advanced monitoring and deliverability tools
- Indie makers building cost-free alternatives to SendGrid/Mailgun
📸 Screenshots / Demo
- Live demo: Self-hosted (no public demo available)
- GitHub: https://github.com/postalserver/postal
🔥 Project Status
- 🟢 Actively building
Last updated: 2026-03-24
❓ FAQ
Is this project free?
Yes — fully open source under MIT License. (Explain briefly.)
Is the source code available?
Yes — link to repository https://github.com/postalserver/postal
Can I contribute?
Yes — open issues/PRs on GitHub, join discussions, share feedback on Discord (https://discord.postalserver.io).
📬 Contact & Links
- Website: https://postalserver.io
- GitHub: https://github.com/postalserver/postal
- Twitter/X: https://x.com/postalserverio
- Email: team@postalserver.io
Built with ❤️ and kept warm on WarmIndex.
Similar apps
The Future of Data & Experience Management | Pimcore
pimcore.com
Fastest time-to-market and rapid digitization with the enterprise data and experience management platform for PIM/MDM, DAM, DXP/CMS, CDP, and digital commerce.
Omeka
omeka.org
Omeka is a free, flexible, and open source web-publishing platform for the display of library, museum, archives, and scholarly collections and exhibitions. Its five-minute setup makes launching an online archive or exhibition as easy as launching a blog.
InvenTree - InvenTree Documentation
docs.inventree.orgenlatest
InvenTree - Open Source Inventory Management
Mantis Bug Tracker
mantisbt.org
MantisBT is a popular free web-based bug tracking system. It is written in PHP works with MySQL, MS SQL, and PostgreSQL databases. MantisBT has been installed on Windows, Linux, Mac OS, OS/2, and others. It is released under the terms of the GNU General Public License (GPL).