Mailcow review covering the Docker-based self-hosted mail server, groupware features, admin UI, pricing, pros and cons, and top alternatives in 2026.
Category
Developer Tools
Pricing
Open Source, from Free (optional paid support/hosting available)
Verified
Not yet
Last updated
July 18, 2026
Headquarters
Willich, Germany (The Infrastructure Company GmbH)
Web AppOpen SourceSelf-Hosted
Overview
Mailcow packages a full open-source email and groupware stack, mail transfer, IMAP, spam and virus filtering, webmail, calendar, and contacts, into a set of Docker containers managed through a single modern admin panel.
It targets administrators who want more feature depth and modularity than a one-script mail server while still avoiding the complexity of assembling each component from scratch, positioning it between minimal setups like Mail-in-a-Box and heavyweight suites like Zimbra.
Key Features
The stack combines Postfix, Dovecot, Rspamd, ClamAV, and SOGo to deliver mail transfer, mailbox access, spam/virus filtering, and groupware (webmail, calendar, contacts, tasks) in one deployment.
Security and deliverability features include enforced TLS, DANE, MTA-STS, automatic Let's Encrypt certificates, outgoing DKIM signing, SPF/DMARC handling, anti-spoofing, greylisting, and malicious attachment blocking, all configurable through the web admin UI.
Pricing
Mailcow is fully open source and free to run under its GPLv3 license, with no separate paid software tier for the core product.
Organizations that don't want to self-manage the Docker stack can pay for commercial support or managed hosting from mailcow's maintaining company or other providers, but this is optional rather than required.
Key Features
Docker-based deployment — Ships as Docker Compose services for portable, consistent installs across environments.
Full mail server stack — Bundles Postfix, Dovecot, Rspamd, and ClamAV for mail transfer, access, spam, and virus filtering.
SOGo groupware and webmail — Includes webmail plus calendar, contacts, and task syncing via CalDAV/CardDAV.
Modern admin UI — Centralized web panel for managing domains, mailboxes, aliases, and quotas.
Strong deliverability defaults — Automatic DKIM, SPF, DMARC, DANE, and MTA-STS configuration to protect sender reputation.
Two-factor authentication — Built-in 2FA support for admin and user accounts.
REST API — Enables automation and integration with external provisioning or management systems.
Multi-domain and per-domain delegation — Supports hosting many domains with delegated per-domain administration.
Pros & Cons
Pros
Completely free and open source with no licensing cost
Includes full groupware (calendar, contacts, tasks), not just email
Modern, actively maintained admin interface compared to older self-hosted options
Strong built-in security and deliverability defaults out of the box
Docker-based architecture makes upgrades and component isolation cleaner
Cons
Requires solid Docker and Linux administration knowledge to run reliably
Higher resource requirements than lighter self-hosted mail options
No official free support channel beyond community forums and Telegram
Initial setup and DNS configuration can be complex for beginners
Self-hosting still requires ongoing IP reputation and maintenance work
Pricing
Self-hosted (Open Source) Free N/A
Frequently Asked Questions
What is mailcow
Mailcow is a free, open-source, Docker-based mail server and groupware suite that combines Postfix, Dovecot, Rspamd, and SOGo behind a modern admin panel.
Is mailcow free to use
Yes, mailcow is open source and free to run; optional paid support and managed hosting are available from third parties but not required.
Does mailcow include webmail and calendar
Yes, mailcow includes SOGo for webmail along with calendar, contacts, and task syncing via CalDAV and CardDAV.
What do I need to run mailcow
Mailcow requires a Linux server with Docker and Docker Compose installed, along with a domain name for DNS and TLS configuration.
Who maintains mailcow
Mailcow is maintained by The Infrastructure Company GmbH, based in Willich, Germany, which also offers commercial support and hosting.
How does mailcow compare to Mail-in-a-Box
Mailcow offers more modularity, groupware features, and a more polished admin UI, while Mail-in-a-Box favors a simpler single-script setup with fewer moving parts.