Mailu Review, Pricing & Features

Mailu review: an open-source, Docker-based mail server bundling Postfix, Dovecot, Rspamd, and Roundcube for self-hosted email. Features and alternatives.

Category
Developer Tools
Pricing
Open Source, from Free
Verified
Not yet
Last updated
July 18, 2026
Founded
2016
Web AppOpen SourceSelf-Hosted

Overview

Mailu is an open-source, self-hosted mail server distribution delivered as a set of Docker images. Instead of manually installing and wiring together Postfix, Dovecot, and a webmail client, administrators use Mailu's setup utility to generate a ready-to-run docker-compose configuration for their domain.

The project started in 2016 as a small Postfix administration interface and has since evolved into a full mail platform combining Postfix (SMTP), Dovecot (IMAP/POP3), Rspamd (spam filtering), and Roundcube (webmail), all released under the MIT license and maintained by an open community of contributors.

Key Features

Mailu bundles a web-based admin interface for managing domains, mailboxes, and aliases, along with an optional webmail client so users can access email directly through a browser. Security is built in by default, with enforced TLS, DANE, MTA-STS, Let's Encrypt certificate automation, outgoing DKIM signing, and antivirus scanning of attachments.

The setup wizard generates the docker-compose.yml and environment files needed to deploy the full stack, which significantly reduces the manual configuration typically required to stand up a production-grade mail server.

Pricing

Mailu itself is completely free and open source under the MIT license; there is no vendor charging for licenses, seats, or mailbox counts. Administrators only pay for the server infrastructure they choose to run it on.

A handful of third-party hosting companies offer managed Mailu deployments for a fee, but these are independent services layered on top of the free, open-source core project.

Key Features

Pros & Cons

Pros

  • Completely free and open source with no licensing costs
  • Docker-based setup significantly simplifies deploying a full mail stack
  • Security features like DANE, MTA-STS, and DKIM are enabled by default
  • Active community maintenance and regular releases
  • Full administrative control over email infrastructure and data

Cons

  • Requires server administration and Docker knowledge to operate
  • Self-hosters are responsible for uptime, backups, and IP reputation
  • Initial mail server reputation can take time to build for good deliverability
  • No official commercial support or SLA from the core project
  • Minimum resource requirements (around 2GB RAM) rule out very small servers

Pricing

Frequently Asked Questions

What is Mailu used for

Mailu is used to self-host a complete email server, including SMTP sending, IMAP/POP3 mailbox access, spam filtering, and webmail, using Docker containers.

Is Mailu free

Yes, Mailu is free and open source under the MIT license, with no charges for licenses, seats, or mailboxes.

What components does Mailu use

Mailu bundles Postfix for mail transport, Dovecot for IMAP/POP3, Rspamd for spam filtering, and Roundcube as an optional webmail client.

Does Mailu support Let's Encrypt

Yes, Mailu automatically provisions and renews TLS certificates through Let's Encrypt integration.

How much server capacity does Mailu need

Mailu recommends at least 2GB of total system memory with 1GB free for running the full stack.

What are alternatives to Mailu

Common alternatives include docker-mailserver, Mail-in-a-Box, iRedMail, Modoboa, and Poste.io, all of which offer self-hosted mail server stacks.

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