Mailu
Mailu: A free, open-source mail stack for teams managing their own email infrastructure. Ranked #18 of 34 in Mail Server Software by our editors (7.4/10); pricing: Free plan; best for simple open-source mail with web administration.
At a glance
- Editor score7.4 / 10
- PricingFree plan
- Best forSimple open-source mail with web administration
- Free planYes
- Paid fromNone
- License modelOpen-source
- Founded2014
- Facts checked21 Sep 2026
Where it wins
- Covers SMTP, IMAP, POP3, webmail, and mail administration
- Includes Rspamd spam filtering and antivirus scanning
- Provides DKIM, DMARC, SPF, and anti-spoofing controls
Where it doesn't
- Requires organizations to operate their own self-hosted mail infrastructure
- Platform coverage centers on web, API, and self-hosted deployment
- Has no commercial paid plan for buyers seeking a paid service tier
Our verdict on Mailu
Mailu is a free, open-source mail server distribution packaged as Docker images. It is designed for people and organizations that want to deploy and operate their own email infrastructure instead of using a hosted mailbox service. The core stack covers SMTP and mail submission, IMAP and POP3 access, browser-based webmail, a web administration interface, aliases, domain aliases, custom routing, quotas, and configuration management through a REST API. Mailu is a practical fit for teams that want broad mail-server fundamentals in one self-hosted distribution.
Its feature depth is strongest around mail delivery, mailbox access, and email protection. Rspamd provides spam filtering, while antivirus scanning and malicious-attachment blocking address another common mail-server concern. Mailu also supports TLS, DKIM, DMARC, SPF, and anti-spoofing controls. Optional WebDAV adds contact and calendar access, and optional services include Fetchmail and attachment search. This gives administrators a wide set of controls without moving to a commercial plan: the published offering is free and open source, with no paid tier described.
The main trade-off is operational ownership. Mailu is Docker-based and self-hosted, so the organization choosing it also takes responsibility for deployment and ongoing mail infrastructure administration. Its published platform options are web, API, and self-hosted, while the available ecosystem and integration coverage are limited compared with products built around broader hosted-service connections. Choose Mailu when control, open-source licensing, web administration, and standard mail protocols matter most. A hosted mailbox service or a platform with wider integrations is a better fit for teams that do not want to run their own mail stack.
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Mailu pricing
Mailu fact sheet
| Free plan | Yes |
|---|---|
| Paid from | None |
| License model | Open-source |
| Webmail interface | Yes |
| IMAP/POP3 access | Yes |
| Mobile sync | Not verified |
| Antispam tools | Yes |
| Mailbox limit | Not verified |
| High availability | Yes |
| Deployment | Self-hosted |
| Platforms | Web |
| Support | Community, Docs |
| Built for | Small business, Mid-market, Enterprise (editorial estimate) |
| Pricing | Free plan |
| Website | mailu.io |
| Facts checked | 21 Sep 2026 |
Alternatives to Mailu
- Microsoft Exchange OnlineA Microsoft-centric hosted mailbox service with Outlook, archiving, compliance, and migration tools.9.3
- Zimbra CollaborationA broad open-source suite for organizations that need email, collaboration, and deployment control.9.1
- IceWarpA broad hosted email suite with collaboration, migration tools, and self-hosted deployment.9.0
Also Ranked In
Mailu is ranked in 2 of our directories.
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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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