Postal vs MailWhale
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
VS
MailWhale
Archived
Self-hosted transactional email relay with API
| Feature | Postal | MailWhale |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 94 · Excellent | 9 · At risk |
| Status | Actively maintained | Archived |
| Category | Mail Servers | Mail Servers |
| License | MIT | MIT |
| Language | Ruby | Go |
| Setup difficulty | Hard | Easy |
| Min. RAM | 2,048 MB | 64 MB |
| Deployment | docker, bare-metal | docker, binary, source |
| GitHub stars | ★ 16,824 | ★ 372 |
| First released | 2017 | 2021 |
| Replaces | SendGrid, Mailgun, Postmark | SendGrid, Postmark |
What are Postal and MailWhale?
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
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
Postal vs MailWhale: key differences
The biggest difference is maintenance: MailWhale's repository is archived and no longer developed, while Postal is actively maintained. Postal is written in Ruby, while MailWhale is built with Go. MailWhale is the lighter option, starting around 64 MB of RAM against 2,048 MB for Postal. Postal is the more established project (first released 2017), while MailWhale arrived in 2021. Postal has the considerably larger community, at 16,824 GitHub stars versus 372.
Why pick each one
Choose Postal if…
- Great for application email
- Strong API
Watch out for
- Multi-component deployment
- Needs careful IP reputation management
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 Postal or MailWhale better?
Neither is universally better. Postal 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 Postal and MailWhale free and open-source?
Yes. Postal is licensed under MIT and MailWhale under MIT. Both can be self-hosted at no software cost.
Can I run Postal and MailWhale with Docker?
Postal: yes. MailWhale: yes.
Which is lighter on resources, Postal or MailWhale?
MailWhale has the smaller minimum footprint at 64 MB of RAM, compared to about 2,048 MB for Postal. Real-world usage depends on library size, user count, and enabled features.