aerc vs RainLoop
A side-by-side comparison of two self-hosted mail servers options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | aerc | RainLoop |
|---|---|---|
| Deploy effort | Read-the-docs project | Under-an-hour setup |
| Status | Actively maintained | Archived |
| Category | Mail Servers | Mail Servers |
| License | MIT | AGPL-3.0 |
| Language | Go | PHP |
| Setup difficulty | Medium | Easy |
| Min. RAM | 64 MB | 128 MB |
| Deployment | binary, source | docker, bare-metal, source |
| GitHub stars | ★ 3,300 | ★ 4,114 |
| First released | 2019 | 2013 |
| Replaces | Gmail, Outlook | Gmail, Outlook Web |
What are aerc and RainLoop?
aerc
aerc is an email client for the terminal designed for power users, with support for multiple accounts, embedded terminal, and a tab-based workflow. It handles IMAP, Maildir, JMAP, and notmuch backends.
- Terminal email client
- Multiple account support
- IMAP, JMAP, and notmuch
- Embedded terminal viewer
RainLoop
RainLoop is a fast, simple webmail client with a modern interface that works with any IMAP and SMTP server. It stores no email data itself, acting as a thin client.
- Modern, responsive UI
- No database required
- Multi-account support
- Works with any IMAP server
aerc vs RainLoop: key differences
The biggest difference is maintenance: RainLoop's repository is archived and no longer developed, while aerc is actively maintained. Aerc is written in Go, while RainLoop is built with PHP. Licensing differs — MIT for aerc versus AGPL-3.0 for RainLoop. Aerc is the lighter option, starting around 64 MB of RAM against 128 MB for RainLoop. RainLoop is the more established project (first released 2013), while aerc arrived in 2019. RainLoop lists first-class Docker deployment; aerc does not.
Why pick each one
Choose aerc if…
- Released under the MIT license
- Active community (3.3k GitHub stars)
- Written in Go
- Tiny footprint — runs in 64 MB RAM
Choose RainLoop if…
- Released under the AGPL-3.0 license
- Easy to set up — beginner-friendly
- First-class Docker support for quick deployment
- Active community (4.1k GitHub stars)
Watch out for
- Development largely stalled
- SnappyMail is the active fork
Frequently asked questions
Is aerc or RainLoop better?
RainLoop is the stronger all-round pick: it has both the larger community and the simpler easy setup. Consider RainLoop if its specific feature set fits your needs better.
Are aerc and RainLoop free and open-source?
Yes. aerc is licensed under MIT and RainLoop under AGPL-3.0. Both can be self-hosted at no software cost.
Can I run aerc and RainLoop with Docker?
aerc: check the project docs for container support. RainLoop: yes.
Which is lighter on resources, aerc or RainLoop?
aerc has the smaller minimum footprint at 64 MB of RAM, compared to about 128 MB for RainLoop. Real-world usage depends on library size, user count, and enabled features.