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The Mailu Insider’s Guide

Everything we know about Mailu in one document: what it costs, its grades, getting a refund, getting help and what else to look at. Read it here, or keep a copy.

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ToolGPANovember 2026

Mailu

The Insider’s Guide

Free Docker-based mail server with webmail and admin UI

Every plan, grade, refund rule and rival among email apps, read from Mailu’s own pages.

Made by Mailu project · checked Nov 13, 2026 · toolgpa.com

2.0GPA

Contents

  1. 01WelcomeWhat it is, who it suits, its grades and the ten things to know first
  2. 02What it costsEvery plan, the free plan, ways to pay less and how prices have moved
  3. 03What it doesIts main features, where it runs, what it works with and who makes it
  4. 04Where it standsIts grades against its category, and whether to keep it or make your own
  5. 05The alternativesThe tools it is most often weighed against, side by side
  6. 06Quick answersThe questions people ask about it, each answered in a line or two
  7. 07About ToolGPAWho made this guide, what else is on the site, and how to cite it

ToolGPA put this guide together from Mailu’s own pages, its app-store listings and our grades. Every fact in it is on Mailu’s page too, where it is kept up to date. Checked Nov 13, 2026.

Part 01 · Overview

Welcome

What it is, who it suits, its grades and the ten things to know first

2.0

GPA, above 11 of the 122 other email apps we grade

Mailu is a mail server packaged as a set of Docker images. It provides IMAP, SMTP and submission, webmail, an admin interface, spam and virus filtering, and DNS and TLS helpers. It is free software maintained by contributors and run on your own server, with Docker Compose and Kubernetes setups documented.

To get you started, here are 8 things to know about Mailu, taken from its own pages and our grades.

You supply the server, DNS, TLS and backups, and the project avoids groupware, so there are no calendars or contacts.
From our report card of Mailu
  1. 1

    Best for a simple Docker mail server

    Mailu is a free Docker-based mail server with webmail and an admin panel.

  2. 2

    It is free

    Mailu has no paid plan at all. The whole mail server is free software; you provide the server, domain and upkeep.

  3. 3

    It runs on Web

    Web.

  4. 4

    Standard mail server

    IMAP, SMTP and submission with auto-configuration profiles for mail clients.

  5. 5

    Webmail and admin interface

    Includes web access to mail and an admin interface with global admins, per-domain delegation, announcements and quotas.

  6. 6

    User mail features

    Aliases, domain aliases, auto-reply, auto-forward, fetched accounts, ManageSieve and full-text search of attachments.

  7. 7

    A 2.0 GPA, above 11 of 122

    That is against the other email apps we grade, on value, the free plan, features, ease of use and platforms.

  8. 8

    Keep it

    Mailu is free, so making your own would save you nothing.

Mailu at a glance

Pricing
Free
Free plan
Yes
Free trial
None stated
Runs on
Web
Made by
Mailu project
Category
Email Apps
Our grade
2.0 GPA, fair

The report card

Best for a simple Docker mail server

Mailu is a free Docker-based mail server with webmail and an admin panel. You supply the server, DNS, TLS and backups, and the project avoids groupware, so there are no calendars or contacts.

ToolGPA report cardMailuGraded Nov 13, 2026
SubjectGradeComment
Value for moneyCFree to run yourself, with a server to provide. The docs ask for 1 GB of memory, or 3 GB with antivirus.
Free plan and trialBThe whole server is free software, with no paid plan. You provide the machine and the upkeep.
FeaturesCStandard mail, webmail, an admin panel, spam filtering and security options. The project says it avoids groupware, so calendars and contacts are missing.
Ease of useDYou run Docker or Kubernetes, DNS records and TLS yourself.
Platforms and integrationsCWeb admin and webmail, with Docker, Kubernetes and Let's Encrypt. No apps of its own.
Grade point averageFair, out of 4.02.0

An A is worth 4 points, a B 3, a C 2, a D 1 and an F nothing. The GPA is the average of the five.

Who Mailu is for

  • Fits if you want your own mail server in Docker and no groupware
  • Works for admins who like plain compose files

Who it is not for

  • Skip it if you want calendars and contacts, since the project says it avoids groupware
  • Skip it if you don't want to run the server, DNS and backups
  • Watch out: support is the community and contributors, and no paid plan exists
  • Watch out: the docs are versioned, so make sure you read the one for your version

Good to know

Good for

  • Self-hosters who want a lean mail server without groupware extras
  • Admins already running Docker or Kubernetes
  • Small organizations hosting mail for their own domains

Worth knowing

  • You provide and maintain the server, DNS records, TLS and backups yourself.
  • The project says it aims to avoid groupware features, so calendars and contacts are not part of the core.
  • Support is from the community and contributors; no paid plan appears on the site.
  • The documentation is versioned, so check you are reading the version you run.

Part 02 · Pricing

What it costs

Every plan, the free plan, ways to pay less and how prices have moved

Free

No paid plan at all

Mailu is free to use.

Free to run yourself, with a server to provide.
From our grade for value for money

  • Mailu

    $0

    Free software you host yourself. The docs list 1 GB of memory without antivirus or 3 GB with it.

The free plan

The whole mail server is free software; you provide the server, domain and upkeep.

Read from mailu.io on Nov 13, 2026.

Part 03 · Features

What it does

Its main features, where it runs, what it works with and who makes it

1

Place it runs: Web

Free Docker-based mail server with webmail and admin UI. Here is what it does, as its own site describes it, and what it covers: open source, self-hostable, email client, dMARC.

Standard mail, webmail, an admin panel, spam filtering and security options.
From our grade for features
Standard mail server
IMAP, SMTP and submission with auto-configuration profiles for mail clients.
Webmail and admin interface
Includes web access to mail and an admin interface with global admins, per-domain delegation, announcements and quotas.
User mail features
Aliases, domain aliases, auto-reply, auto-forward, fetched accounts, ManageSieve and full-text search of attachments.
Security options
Enforced TLS, DANE, MTA-STS, Let's Encrypt, outgoing DKIM, an antivirus scanner and blocking of malicious attachments.
Spam filtering
Auto-learning, greylisting, DMARC and SPF checks and anti-spoofing.
Compose and Kubernetes setups
Documented Docker Compose and Kubernetes installs, a RESTful API and a command line for administration.

Where it runs

  • Web

What it works with

  • Docker
  • Kubernetes
  • Let's Encrypt

Mailu is made by Mailu project.

Part 04 · Standing

Where it stands

Its grades against its category, and whether to keep it or make your own

11/122

Other email apps it is graded above

Mailu's GPA of 2.0 is higher than 11 of the 122 other email apps we grade, and level with 17.

It stands best on free plan and trial (B, above 69 of 122) and worst on ease of use (D, above 0).

Mailu has no paid plan.

On features, ease of use and platforms it scores 1.7 out of 4. Nothing scores higher for less, though at least one tool matches that score at a lower price.

Each grade against the category

Every bar is all 123 email apps we grade, cut by the letter each got. Mailu’s own letter is outlined.

  • CValue for moneyAbove 13 of 122
  • BFree plan and trialAbove 69 of 122
  • CFeaturesAbove 1 of 122
  • DEase of useAbove 0 of 122
  • CPlatforms and integrationsAbove 10 of 122

Price against what you get

Each dot is one of 107 email apps. Further left costs less; higher up scores better on features, ease of use and platforms. Mailu is the marked dot.

D1.0C2.0B3.0A4.0Free$0.5$1$2$5$10$20$50$100More for lessCosts more, scores moreCosts less, scores lessCosts more, scores lessMailuMicrosoft OutlookZoho MailUnroll.MeThunderbird

What paid plans start at, a month (each step along is roughly double) →

Keep it, or make your own?

Whether this is something you could build for yourself with an AI app builder, and what you would give up.

Keep it

Mailu is free, so making your own would save you nothing.

And it is not the kind of software a weekend replaces. That makes this kind of software worth paying for, not this one in particular: 94 of the 122 other email apps grade higher.

What you could not

  • An email client: sending, receiving, threading and searching years of mail.
  • Reading the reports inbox providers send about your domain.

What this rests on. Mailu’s listing: what it does, where it runs, what it plugs into and what it costs. It is a judgement about the kind of software this is. We have not built a replacement for it, and making your own means looking after it too. How we decide, and every tool’s verdict.

Part 05 · Alternatives

The alternatives

The tools it is most often weighed against, side by side

mailcow, Mail-in-a-Box, docker-mailserver, Modoboa and Stalwart Mail Server

The 5 tools Mailu is most often weighed against, with where each one differs from it.

Part 06 · Questions

Quick answers

The questions people ask about it, each answered in a line or two

12

Questions, each answered in a line or two

The short version of everything above, for when you only need the answer. Each one is told in full in its part of the guide.

Is Mailu free?

Yes. Mailu is free to use.

How much does Mailu cost?

Mailu lists one plan. Mailu: $0.

What platforms does Mailu work on?

Mailu is available on Web.

Does Mailu have an Android app?

No Android app was listed when its pages were read on Nov 13, 2026. Mailu is listed for Web.

Does Mailu have an iPhone app?

No iPhone app was listed when its pages were read on Nov 13, 2026. Mailu is listed for Web.

Is Mailu open source?

Yes. Mailu is open source, according to its own site.

What does Mailu integrate with?

Mailu's listing names Docker, Kubernetes and Let's Encrypt. A listing names up to eight integrations, so it may connect to more.

Who makes Mailu?

Mailu is made by Mailu project.

What are the alternatives to Mailu?

The closest alternatives to Mailu in our directory are mailcow, Mail-in-a-Box, docker-mailserver, Modoboa and Stalwart Mail Server.

How does Mailu compare with other email apps?

Mailu's GPA of 2.0 is higher than 11 of the 122 other email apps we grade, and level with 17.

Is Mailu good value for money?

ToolGPA grades Mailu C for value for money. Mailu has no paid plan.

Could I make my own version of Mailu?

Mailu is free, so making your own would save you nothing. And it is not the kind of software a weekend replaces.

Where this guide comes from

The prices, plans, platforms and features were read from Mailu’s own pages on Nov 13, 2026, and the grades were given on Nov 13, 2026. Graded from this listing, whose facts were read from the Mailu project's own pages on 13 November 2026. Not based on using the product, and shorter than our full reviews.

Every tool we list gets five grades, A to F, each with its reason, and a GPA that averages them. How each is decided is at toolgpa.com/grades. This guide is ToolGPA’s own work; it is not made, paid for or approved by Mailu project. Prices change, so check mailu.io before you buy.

Part 07 · About

About ToolGPA

Who made this guide, what else is on the site, and how to cite it

7,721

Tools graded, in 95 categories

ToolGPA grades software the way a school report grades a pupil: five subjects, a letter for each with the reason written beside it, and a GPA that averages them. Prices, plans and platforms are read from each maker’s own pages and dated, so you always know how fresh a figure is.

Every grade, review and ranking on ToolGPA is our own judgement. No company can pay for a grade or change one. Every tool on the site has a guide like this one, free to download and pass on. It all lives at toolgpa.com.

  • 7,721

    tools graded

  • 95

    categories

  • 739

    price changes on record

  • 579

    apps priced in 12 countries

What else is on toolgpa.com

Scan for the live page

Prices and grades as they are today

Quoting this guide?

Please name ToolGPA and link to the live page, so readers can check the figures for themselves:

ToolGPA, "Mailu: The Insider's Guide", checked Nov 13, 2026. https://toolgpa.com/tools/mailu

Know someone choosing between email apps?

Send them this guide: toolgpa.com/tools/mailu/guide

ToolGPA elsewhere: youtube.com/@toolgpa

See our other guides

The best-graded email apps after Mailu, each with an Insider's Guide of its own.

ToolGPA

Choosing software? Every tool graded, every price dated.

Compare tools at toolgpa.com ›

Everything in this guide is ToolGPA’s own summary of what Mailu’s pages, its app-store listings and public reviews said on the dates shown. Grades are our judgement under the rules at toolgpa.com/grades. Every grade, review and ranking on ToolGPA is our own judgement. No company can pay for a grade or change one. Mailu is a trademark of its owner, and this guide is not made, paid for or approved by Mailu project. Prices and plans change: check mailu.io before you buy.