Postorius vs Schleuder
A side-by-side comparison of two self-hosted mail servers options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | Postorius | Schleuder |
|---|---|---|
| Deploy effort | Under-an-hour setup | Read-the-docs project |
| Category | Mail Servers | Mail Servers |
| License | GPL-3.0 | GPL-3.0 |
| Language | Python | Ruby |
| Setup difficulty | Hard | Hard |
| Min. RAM | 512 MB | 256 MB |
| Deployment | docker, source | bare-metal, source |
| GitHub stars | ★ 200 | ★ 100 |
| First released | 2012 | 2009 |
| Replaces | Google Groups | Google Groups |
What are Postorius and Schleuder?
Postorius
Postorius is the official Django-based web frontend for administering Mailman 3 mailing lists. It lets list owners and administrators manage subscriptions, settings, and moderation through a browser.
- Mailman 3 admin UI
- Subscription management
- Moderation controls
- Django integration
Schleuder
Schleuder is a mailing list manager designed for groups that need encrypted communication, decrypting incoming and re-encrypting outgoing mail with OpenPGP. It also serves as a remailer for confidential teams.
- OpenPGP encrypted lists
- Re-encrypts for each member
- Remailer functionality
- Key management
Postorius vs Schleuder: key differences
Postorius is written in Python, while Schleuder is built with Ruby. Schleuder is the lighter option, starting around 256 MB of RAM against 512 MB for Postorius. Schleuder is the more established project (first released 2009), while Postorius arrived in 2012. Postorius has the considerably larger community, at 200 GitHub stars versus 100. Postorius lists first-class Docker deployment; Schleuder does not.
Why pick each one
Choose Postorius if…
- Released under the GPL-3.0 license
- First-class Docker support for quick deployment
- Written in Python
- Lightweight — runs in 512 MB RAM
Choose Schleuder if…
- Released under the GPL-3.0 license
- Written in Ruby
- Tiny footprint — runs in 256 MB RAM
Frequently asked questions
Is Postorius or Schleuder better?
Neither is universally better. Postorius has the larger community; both share a hard setup difficulty, so the decision comes down to features and licensing.
Are Postorius and Schleuder free and open-source?
Yes. Postorius is licensed under GPL-3.0 and Schleuder under GPL-3.0. Both can be self-hosted at no software cost.
Can I run Postorius and Schleuder with Docker?
Postorius: yes. Schleuder: check the project docs for container support.
Which is lighter on resources, Postorius or Schleuder?
Schleuder has the smaller minimum footprint at 256 MB of RAM, compared to about 512 MB for Postorius. Real-world usage depends on library size, user count, and enabled features.