Haraka vs Postal
A side-by-side comparison of two self-hosted mail servers options — licensing, setup difficulty, resource needs, and what each one replaces.
Postal
Complete mail delivery platform for outgoing email
| Feature | Haraka | Postal |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 90 · Excellent | 94 · Excellent |
| Category | Mail Servers | Mail Servers |
| License | MIT | MIT |
| Language | JavaScript | Ruby |
| Setup difficulty | Medium | Hard |
| Min. RAM | 256 MB | 2,048 MB |
| Deployment | docker, bare-metal, source | docker, bare-metal |
| GitHub stars | ★ 5,617 | ★ 16,824 |
| First released | 2011 | 2017 |
| Replaces | SendGrid, Mailgun | SendGrid, Mailgun, Postmark |
What are Haraka and Postal?
Haraka
Haraka is a fast, highly extensible SMTP server written in Node.js. Its event-driven plugin architecture makes it well suited for custom mail handling and high-volume delivery.
- Event-driven plugin system
- Very high throughput
- Inbound and outbound handling
- JavaScript plugin development
Postal
Postal is a full-featured, self-hosted mail server designed for sending and receiving email for websites and applications. It is a self-hosted alternative to transactional email services.
- Transactional email sending
- Detailed delivery analytics
- HTTP API and webhooks
- Multi-organization support
Haraka vs Postal: key differences
Haraka is written in JavaScript, while Postal is built with Ruby. Haraka is the lighter option, starting around 256 MB of RAM against 2,048 MB for Postal. Haraka is the more established project (first released 2011), while Postal arrived in 2017. Postal has the considerably larger community, at 16,824 GitHub stars versus 5,617.
Why pick each one
Choose Haraka if…
- Highly customizable
- Excellent performance
Watch out for
- SMTP only, no mailbox access
- Requires coding for advanced features
Choose Postal if…
- Great for application email
- Strong API
Watch out for
- Multi-component deployment
- Needs careful IP reputation management
Frequently asked questions
Is Haraka or Postal better?
Neither is universally better. Postal has the larger community, while Haraka is simpler to set up (medium difficulty). Choose based on the comparison table above and your own setup.
Are Haraka and Postal free and open-source?
Yes. Haraka is licensed under MIT and Postal under MIT. Both can be self-hosted at no software cost.
Can I run Haraka and Postal with Docker?
Haraka: yes. Postal: yes.
Which is lighter on resources, Haraka or Postal?
Haraka has the smaller minimum footprint at 256 MB of RAM, compared to about 2,048 MB for Postal. Real-world usage depends on library size, user count, and enabled features.