Chatmail Relay vs Delta Chat
A side-by-side comparison of two self-hosted chat & communication options — licensing, setup difficulty, resource needs, and what each one replaces.
Delta Chat
Decentralized messenger built on top of email
| Feature | Chatmail Relay | Delta Chat |
|---|---|---|
| Deploy effort | Under-an-hour setup | Read-the-docs project |
| Health score | 79 · Good | 82 · Excellent |
| Category | Chat & Communication | Chat & Communication |
| License | MPL-2.0 | MPL-2.0 |
| Language | Python | Rust |
| Setup difficulty | Medium | Medium |
| Min. RAM | 512 MB | 256 MB |
| Deployment | docker, bare-metal | bare-metal, binary |
| GitHub stars | ★ 484 | ★ 929 |
| First released | 2023 | 2017 |
| Replaces | WhatsApp, Signal | WhatsApp, Signal, Telegram |
What are Chatmail Relay and Delta Chat?
Chatmail Relay
A minimal, opinionated mail server configuration optimized to act as a relay for Delta Chat clients, providing instant, encrypted messaging over standard email. It is provisioned automatically for low-maintenance operation.
- Email-based messaging
- Automatic provisioning
- End-to-end encryption
- Low maintenance
Delta Chat
Delta Chat is a messaging app that uses standard email servers as its transport, providing chat-like UX with end-to-end encryption. Any IMAP/SMTP mail server can serve as the self-hosted backend.
- Uses existing email infrastructure
- Autocrypt end-to-end encryption
- No phone number required
- Cross-platform clients
Chatmail Relay vs Delta Chat: key differences
Chatmail Relay is written in Python, while Delta Chat is built with Rust. Delta Chat is the lighter option, starting around 256 MB of RAM against 512 MB for Chatmail Relay. Delta Chat is the more established project (first released 2017), while Chatmail Relay arrived in 2023. Chatmail Relay lists first-class Docker deployment; Delta Chat does not.
Why pick each one
Choose Chatmail Relay if…
- Uses open email standards
- Hard to censor
Watch out for
- Requires mail server knowledge
- Newer project
Choose Delta Chat if…
- Leverages decentralized email
- No new server protocol
Watch out for
- Email latency for messages
- Needs an IMAP/SMTP account
Frequently asked questions
Is Chatmail Relay or Delta Chat better?
Neither is universally better. Delta Chat has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are Chatmail Relay and Delta Chat free and open-source?
Yes. Chatmail Relay is licensed under MPL-2.0 and Delta Chat under MPL-2.0. Both can be self-hosted at no software cost.
Can I run Chatmail Relay and Delta Chat with Docker?
Chatmail Relay: yes. Delta Chat: check the project docs for container support.
Which is lighter on resources, Chatmail Relay or Delta Chat?
Delta Chat has the smaller minimum footprint at 256 MB of RAM, compared to about 512 MB for Chatmail Relay. Real-world usage depends on library size, user count, and enabled features.