mailcow is a free, open-source mail server suite (GPL-3.0) that runs Postfix, Dovecot, Rspamd, ClamAV and SOGo webmail in Docker, managed from a web panel. It is for admins who want to host their own email on a Linux VM with at least 6 GiB of RAM. Self-hosting costs nothing; the maintainer's hosted plans start at EUR 8.90 a month.
The bottom line
The pick for admins who want a full-featured mail server for free and can run Linux and Docker.
7.1
Our score
7.1 / 10
Conversion Gems editorial verdict
Free (self-hosted); hosted from EUR 8.90/mo gross
Features8/10
8 - SMTP, IMAP, POP3, Rspamd, ClamAV, SOGo groupware, ACME and a web admin UI in one deployment.
Value9/10
9 - free under GPL-3.0 with no mailbox limits; paid hosting and support are optional.
Ease of use4/10
4 - needs a full VM with 6 GiB RAM, Docker, open mail ports and correct DNS; specialist setup.
Ecosystem6/10
6 - standard mail protocols, x86_64 and ARM64 builds and SOGo, but no integration marketplace.
Support7/10
7 - docs, community forum and Telegram, plus paid ticket, phone and remote support tiers.
What it really is
A free, preassembled Docker mail server with groupware and a web admin panel.
Our take
mailcow saves you from wiring Postfix, Dovecot and spam filtering together by hand, and the admin UI is friendly for a self-hosted tool. You still own the hard parts of email: IP reputation, DNS records, backups and updates. Size the server for 6 GiB of RAM and plan for monitoring.
Why we rate it
It bundles a complete, maintained mail stack with groupware and a web UI at no license cost.
The catch
Heavy RAM needs and full responsibility for deliverability and upkeep.
Best for
Sysadmins comfortable with Linux and Docker
Small businesses that want data on their own server
Homelab users hosting several domains
Not good for
Teams with no Linux skills
Hosts limited to LXC or OpenVZ containers
Friction report
Time to value
Hours: prepare a VM, set DNS records, clone the repo, generate the config and start the containers.
Scale breakpoint
Growth is limited by your server; when upkeep becomes a burden, the next step is paid support or managed hosting.
Walled garden
Low: open source, standard IMAP, SMTP and POP3, so mail can move to any other server.
mailcow costs: self-hosted, hosted and support
Option
Price
What you get
Self-hosted mailcow: dockerized
Free (GPL-3.0)
Full mail stack on your own server; community forum and Telegram help
Shared mailcow (Servercow)
From EUR 8.90/mo
1 domain, 20 mailboxes, up to 50 GB, self-service support
Managed mailcow (Servercow)
From EUR 54.90/mo
Dedicated server, clean IPs, up to 500 GB, developer support
Support Ticket (L1)
EUR 45.90/mo
3 tickets per quarter, response within 1 day
Support Emergency (L4)
EUR 430 one-time
120 minutes phone and remote help, response within 2 hours
From mailcow's GitHub repository and the Servercow mailcow page, checked 4 October 2026. Servercow prices are gross and include 19% German VAT.
Minimum server requirements
Item
Requirement
CPU
1 GHz
RAM
6 GiB plus 1 GiB swap (default config)
Disk
20 GiB, not counting email
Architecture
x86_64 or ARM64
Virtualization
Full VM (KVM, ESX, Hyper-V); no OpenVZ, Virtuozzo or LXC
From the mailcow documentation, checked 4 October 2026.
Frequently Asked Questions
Yes. mailcow: dockerized is open source under GPL-3.0 and free to self-host. Paid extras exist: hosted mailcow from EUR 8.90 a month and support packages from EUR 45.90 a month, both gross prices from Servercow (checked 4 October 2026).
Running your own email server. It handles sending and receiving mail, spam and virus filtering, webmail, calendars and contacts for one or many domains, all managed from a web panel.
The docs list a 1 GHz CPU, 6 GiB RAM plus 1 GiB swap, 20 GiB disk before email, and x86_64 or ARM64. It needs full virtualization such as KVM, ESX or Hyper-V; OpenVZ, Virtuozzo and LXC are not supported.
The official project is built for Docker and Docker Compose; its name, mailcow: dockerized, reflects that. The install guide assumes Docker on a supported Linux distribution.
It is one of the most complete free options. Mailu is lighter on memory, and SmarterMail suits teams that want a commercial product on Windows Server or Linux. Pick mailcow if you want groupware included and can give it 6 GiB of RAM.
mailcow alternatives
Other self-hosted or developer email options:
Mailu: Lighter Docker mail server under the MIT license, with Roundcube webmail.
SmarterMail: Commercial mail and groupware server for Windows Server and Linux, with a small free edition.
Amazon SES: Cloud email sending service for apps that only need outbound and transactional mail.
