DragonFly Mail Agent vs OpenSMTPD
A side-by-side comparison of two self-hosted mail servers options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | DragonFly Mail Agent | OpenSMTPD |
|---|---|---|
| Deploy effort | Read-the-docs project | Read-the-docs project |
| Health score | 71 · Good | 80 · Excellent |
| Category | Mail Servers | Mail Servers |
| License | BSD-3-Clause | ISC |
| Language | C | C |
| Setup difficulty | Easy | Medium |
| Min. RAM | 32 MB | 32 MB |
| Deployment | binary, source | bare-metal, source |
| GitHub stars | ★ 265 | ★ 586 |
| First released | 2008 | 2013 |
| Replaces | Sendmail, Postfix | Sendmail, Postfix |
What are DragonFly Mail Agent and OpenSMTPD?
DragonFly Mail Agent
DragonFly Mail Agent (dma) is a small mail transport agent that accepts mail from the local system and either delivers it locally or forwards it to a smarthost. It is designed for systems that do not need a full MTA.
- Tiny mail transport agent
- Smarthost forwarding
- Local delivery
- Minimal footprint
OpenSMTPD
OpenSMTPD is a free implementation of the SMTP protocol developed by the OpenBSD project. It emphasizes simplicity, security, and a readable configuration syntax for running your own mail relay or server.
- Simple configuration
- Security focused
- SMTP relay and delivery
- Filters via extensions
DragonFly Mail Agent vs OpenSMTPD: key differences
Both projects are written in C. Licensing differs — BSD-3-Clause for DragonFly Mail Agent versus ISC for OpenSMTPD. DragonFly Mail Agent is the more established project (first released 2008), while OpenSMTPD arrived in 2013. OpenSMTPD has the considerably larger community, at 586 GitHub stars versus 265.
Why pick each one
Choose DragonFly Mail Agent if…
- Released under the BSD-3-Clause license
- Easy to set up — beginner-friendly
- Written in C
- Tiny footprint — runs in 32 MB RAM
Choose OpenSMTPD if…
- Clean concise config
- Strong security record
Watch out for
- Fewer features than Postfix
- Smaller ecosystem
Frequently asked questions
Is DragonFly Mail Agent or OpenSMTPD better?
Neither is universally better. OpenSMTPD has the larger community, while DragonFly Mail Agent is simpler to set up (easy difficulty). Choose based on the comparison table above and your own setup.
Are DragonFly Mail Agent and OpenSMTPD free and open-source?
Yes. DragonFly Mail Agent is licensed under BSD-3-Clause and OpenSMTPD under ISC. Both can be self-hosted at no software cost.
Can I run DragonFly Mail Agent and OpenSMTPD with Docker?
DragonFly Mail Agent: check the project docs for container support. OpenSMTPD: check the project docs for container support.