Cuttlefish vs MailWhale
A side-by-side comparison of two self-hosted mail servers options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | Cuttlefish | MailWhale |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 19 · At risk | 9 · At risk |
| Status | Actively maintained | Archived |
| Category | Mail Servers | Mail Servers |
| License | AGPL-3.0 | MIT |
| Language | Ruby | Go |
| Setup difficulty | Medium | Easy |
| Min. RAM | 1,024 MB | 64 MB |
| Deployment | docker, bare-metal, source | docker, binary, source |
| GitHub stars | ★ 1,623 | ★ 372 |
| First released | 2014 | 2021 |
| Replaces | Mailgun, SendGrid, Postmark | SendGrid, Postmark |
What are Cuttlefish and MailWhale?
Cuttlefish
Cuttlefish is a self-hosted transactional email server that sends application email and tracks deliveries, opens, and clicks. It provides a dashboard for monitoring email performance.
- Transactional email delivery
- Open and click tracking
- Delivery monitoring dashboard
- SMTP relay interface
MailWhale
MailWhale is a self-hosted SMTP relay that gives applications a simple way to send transactional email, with an HTTP API, multiple sender identities, and per-application access control.
- Self-hosted transactional email relay
- HTTP API for sending mail
- Per-application access control
Cuttlefish vs MailWhale: key differences
The biggest difference is maintenance: MailWhale's repository is archived and no longer developed, while Cuttlefish is actively maintained. Cuttlefish is written in Ruby, while MailWhale is built with Go. Licensing differs — AGPL-3.0 for Cuttlefish versus MIT for MailWhale. MailWhale is the lighter option, starting around 64 MB of RAM against 1,024 MB for Cuttlefish. Cuttlefish is the more established project (first released 2014), while MailWhale arrived in 2021. Cuttlefish has the considerably larger community, at 1,623 GitHub stars versus 372.
Why pick each one
Choose Cuttlefish if…
- Released under the AGPL-3.0 license
- First-class Docker support for quick deployment
- Active community (1.6k GitHub stars)
- Written in Ruby
Watch out for
- Outbound mail only
- Slower development
Choose MailWhale if…
- Released under the MIT license
- Easy to set up — beginner-friendly
- First-class Docker support for quick deployment
- Written in Go
Frequently asked questions
Is Cuttlefish or MailWhale better?
Neither is universally better. Cuttlefish has the larger community, while MailWhale is simpler to set up (easy difficulty). Choose based on the comparison table above and your own setup.
Are Cuttlefish and MailWhale free and open-source?
Yes. Cuttlefish is licensed under AGPL-3.0 and MailWhale under MIT. Both can be self-hosted at no software cost.
Can I run Cuttlefish and MailWhale with Docker?
Cuttlefish: yes. MailWhale: yes.
Which is lighter on resources, Cuttlefish or MailWhale?
MailWhale has the smaller minimum footprint at 64 MB of RAM, compared to about 1,024 MB for Cuttlefish. Real-world usage depends on library size, user count, and enabled features.