Mailu vs Docker Mail Server Compared

Both Mailu and Docker Mail Server (DMS) are Docker-based email solutions built on Postfix + Dovecot. They share the same core mail engine but differ significantly in philosophy: Mailu provides a web UI for everything; DMS gives you a CLI tool and config files.

Overview

Mailu packages a full mail suite: Postfix (SMTP), Dovecot (IMAP), Rspamd (anti-spam), a Flask admin panel, and optional Roundcube/Rainloop webmail — all in coordinated Docker containers with a web-based setup wizard. Point, click, configure.

Docker Mail Server (DMS) runs Postfix + Dovecot + OpenDKIM + Amavis/Rspamd in a single container, managed through setup.sh CLI commands and environment variables. No web admin, no setup wizard — just config files and a shell script. Closer to a traditional mail server, containerized.

Feature Comparison

Feature	Mailu	Docker Mail Server
Admin interface	Web UI (Flask)	CLI (setup.sh)
Setup wizard	Yes (setup.mailu.io)	No
Webmail	Roundcube/Rainloop (bundled)	None (bring your own)
Spam filter	Rspamd (integrated)	Amavis + SpamAssassin or Rspamd
Antivirus	ClamAV (optional)	ClamAV (optional)
DKIM	Automatic (admin UI)	setup.sh config dkim
User management	Web UI	setup.sh email add
Alias management	Web UI	Config file or setup.sh
Auto-discovery	Yes (Outlook/Thunderbird)	Optional (extra config)
Container count	6-8	1
Fetchmail	Yes (integrated)	Yes
Quotas	Yes (per-user, web UI)	Yes (config)
Multi-domain	Yes	Yes
Fail2ban	Built-in	Built-in
Let’s Encrypt	Built-in	Bring your own or Traefik
IPv6	Yes	Yes
Documentation	Good (official docs + wizard)	Excellent (comprehensive)

Setup Experience

Mailu has the easiest setup of any self-hosted email solution. Go to setup.mailu.io, answer questions (domain, TLS approach, optional components), and download a generated docker-compose.yml + .env. Deploy it, set DNS records, and your mail server is running. Adding users, domains, and aliases happens through the web admin.

DMS requires more manual work. Clone the repo (or pull the image), create a compose.yaml, configure environment variables in mailserver.env, and use setup.sh to add email accounts:

docker exec -it mailserver setup email add [email protected] password
docker exec -it mailserver setup config dkim keysize 2048 domain example.com

No wizard, no web interface. All configuration happens through the CLI or config files. DMS’s documentation is thorough — arguably the best of any self-hosted email project — but you’re reading docs and typing commands, not clicking buttons.

Architecture

Mailu’s multi-container approach:

• front — Nginx reverse proxy + TLS termination
• admin — Flask admin panel + user management
• imap — Dovecot IMAP/POP3
• smtp — Postfix SMTP
• antispam — Rspamd
• webmail — Roundcube or Rainloop (optional)
• fetchmail — external email fetching (optional)
• webdav — Radicale CalDAV/CardDAV (optional)

Each component runs in its own container with dedicated resources. Debugging requires identifying which container has the issue.

DMS’s single-container approach:

• One container running Postfix, Dovecot, OpenDKIM, and optionally Amavis/SpamAssassin/ClamAV

Everything in one container. Simpler deployment, simpler logs (docker logs mailserver), simpler resource tracking. The trade-off: less isolation between components.

Resource Usage

Metric	Mailu (standard)	Docker Mail Server
RAM (idle)	400-600MB	200-350MB
RAM (with ClamAV)	800MB-1.2GB	600-900MB
Containers	6-8	1
Disk (base)	~1GB	~500MB
CPU (idle)	Higher (multiple processes)	Lower (single container)

DMS is leaner because it runs fewer processes (no admin panel, no webmail, no separate front proxy). ClamAV adds significant RAM to both — skip it if you’re on a small VPS and rely on Rspamd/SpamAssassin alone for spam filtering.

Spam Filtering

Mailu integrates Rspamd with a pre-tuned configuration. Rspamd is the more modern spam filter — machine learning classification, neural networks, greylisting, DKIM/SPF/DMARC verification, and rate limiting. Mailu’s integration is tight — the admin UI shows spam statistics and lets you adjust settings.

DMS supports both Amavis + SpamAssassin (default, legacy) and Rspamd (opt-in). SpamAssassin is older but well-proven. Rspamd on DMS requires opt-in configuration but gives the same filtering quality as Mailu’s Rspamd integration once enabled.

For spam filtering out of the box: Mailu wins (Rspamd pre-configured). DMS requires choosing and configuring your spam filter.

Community and Support

Metric	Mailu	Docker Mail Server
GitHub stars	~5,800	~14,000+
Contributors	~100	~200+
Documentation	Good	Excellent
Troubleshooting guides	Some	Extensive
Update frequency	Regular	Very regular

DMS has a larger community, more contributors, and better documentation. The docs cover edge cases, complex setups, and troubleshooting in depth. Mailu’s docs are good but less comprehensive. For a first-time self-hosted email setup, DMS’s documentation reduces the chance of getting stuck.

Use Cases

Choose Mailu If…

• You want a web admin panel for managing users, domains, and aliases
• You want bundled webmail (Roundcube) without deploying a separate container
• You prefer a setup wizard that generates your configuration
• You want automatic DKIM key generation through the UI
• You need CalDAV/CardDAV (Radicale integration)
• You prefer managing email through a browser, not a terminal

Choose Docker Mail Server If…

• You want the lightest possible email setup
• You prefer CLI management and config files over web UIs
• You want the best documentation in the self-hosted email space
• You already have a reverse proxy and webmail and don’t want duplicates
• You value single-container simplicity for deployment and backups
• You need maximum flexibility in component choice (Rspamd vs SpamAssassin, etc.)

Final Verdict

For self-hosters who want email management through a web UI, pick Mailu. The admin panel, setup wizard, and bundled webmail make it the most accessible self-hosted email suite. You trade some resource overhead for significant convenience.

For self-hosters who are comfortable with the CLI, pick Docker Mail Server. It’s lighter, better documented, has a larger community, and the single-container architecture is simpler to operate. You supply your own webmail and admin tools, but you get more control over each component.

Both produce the same end result: a fully functional email server with Postfix, Dovecot, and spam filtering. The choice is really about management interface preference.

FAQ

Can I add a web admin to Docker Mail Server?

Not natively, but you can run tools like Mailcow’s SOGo or a separate admin panel alongside DMS. Some users pair DMS with custom scripts or LDAP for user management. DMS intentionally avoids bundling a web UI to stay lean.

Which has better deliverability?

Identical. Both use Postfix for SMTP with proper DKIM signing, SPF, and DMARC. Deliverability depends on your DNS configuration and IP reputation, not the mail server software.

Can I migrate between Mailu and DMS?

Yes. Export mailboxes via IMAP sync (using imapsync or similar tools). DNS records (MX, SPF, DKIM, DMARC) need updating to point to the new server. User accounts must be recreated in the new system.

Related

• How to Self-Host Mailu
• How to Self-Host Docker Mail Server
• Mailu vs Mailcow
• Mailu vs Stalwart
• Mailcow vs Docker Mail Server
• Best Self-Hosted Email Servers
• Self-Hosted Alternatives to Gmail
• Docker Compose Basics