MailCatcher vs Mailspring
A side-by-side comparison of two self-hosted mail servers options — licensing, setup difficulty, resource needs, and what each one replaces.
Not the right match-up?
MailCatcher
Catch-all SMTP server for inspecting test email
VS
Mailspring
Cross-platform desktop email client
| Feature | MailCatcher | Mailspring |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | MIT | GPL-3.0 |
| Language | Ruby | JavaScript |
| Setup difficulty | Easy | Easy |
| Min. RAM | 128 MB | 512 MB |
| Deployment | docker, binary, source | binary, source |
| GitHub stars | ★ 6,774 | ★ 17,730 |
| First released | 2010 | 2017 |
| Replaces | Mailtrap | Outlook, Apple Mail |
Why pick each one
Choose MailCatcher if…
- Released under the MIT license
- Easy to set up — beginner-friendly
- First-class Docker support for quick deployment
- Mature project with 6.8k GitHub stars
Choose Mailspring if…
- Released under the GPL-3.0 license
- Easy to set up — beginner-friendly
- Mature project with 17.7k GitHub stars
- Written in JavaScript
Frequently asked questions
Is MailCatcher or Mailspring better?
Neither is universally better. Mailspring has the larger community; both share a easy setup difficulty, so the decision comes down to features and licensing.
Are MailCatcher and Mailspring free and open-source?
Yes. MailCatcher is licensed under MIT and Mailspring under GPL-3.0. Both can be self-hosted at no software cost.
Can I run MailCatcher and Mailspring with Docker?
MailCatcher: yes. Mailspring: check the project docs for container support.