Mailcow
Self-hosted email server suite with a modern web UI.
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Use it free
Open the official tool or demo — no account needed.
Self-host it
Run the open-source version on your own infrastructure.
What is Mailcow?
Mailcow is an open-source email server solution designed to provide secure, scalable, and customizable email services for individuals and organizations. Built on Docker containers, it integrates core components like Postfix, Dovecot, and Rspamd to handle email routing, storage, and spam filtering. The project caters to system administrators, small-to-medium businesses, and developers seeking to self-host email infrastructure. It addresses challenges such as spam filtering, email security, and centralized management of email domains, offering a alternative to proprietary email services. By leveraging Docker, Mailcow simplifies deployment while allowing granular control over configuration, making it suitable for environments requiring compliance with specific security standards or data sovereignty requirements.
How it works
Mailcow is a dockerized email server suite that combines Postfix, Dovecot, Rspamd, and Nginx to deliver a comprehensive email infrastructure. Its primary purpose is to provide a secure, scalable, and easy-to-manage email solution for users who need full control over their email services. The tool is particularly useful for organizations requiring advanced spam filtering, email encryption, and domain management. Its modular architecture allows customization for specific use cases, such as handling high-volume email traffic or meeting compliance regulations. Mailcow excels in spam and malware filtering through integration with Rspamd, which uses machine learning and rule-based detection. It also supports DKIM, DMARC, and SPF for email authentication, reducing phishing risks. Recent updates (e.g., Rspamd 4.1.4, Nginx 1.30.3) address critical security vulnerabilities, ensuring ongoing protection against emerging threats.
How to use it
- 1Install Docker and Docker Compose on your server. 2. Clone the Mailcow repository from GitHub and navigate to the project directory. 3. Edit the configuration files (e.g., `docker-compose.yml`, `config/nginx.conf`) to set domain names, admin credentials, and security parameters. 4. Run `docker-compose up -d` to deploy the containers. 5. Access the web interface (typically at `http://<server-ip>:80`) to configure email domains and user accounts. Practical tips: Ensure your server meets minimum hardware requirements (e.g., 2GB RAM). Use HTTPS with Let's Encrypt for secure access. Regularly update components via the provided changelogs to address security patches like CVE-2026-33278.
What it can do
- mail server
Use cases
Assumptions and limitations
Assumptions
- source: https://github.com/mailcow/mailcow-dockerized
- license: GPL-3.0 — free to use
- privacy: Self-hosted — you control your data
Limitations
- Requires technical expertise to configure Docker and security settings
- Dependent on stable internet connectivity for updates and Let's Encrypt certificate renewals
- Limited built-in GUI for advanced configuration compared to commercial alternatives
- Manual setup of DNS records and email authentication protocols (DKIM/DMARC)
- Resource-intensive for low-end hardware (minimum 2GB RAM recommended)
Understanding the result
Self-hosted email server suite with a modern web UI.
Tool details
- Clearly flagged when a network request is needed.
- No account, no sign-up, and no tracking of your content.
- Powered by (GPL-3.0).
- Built with
- (mailcow/mailcow-dockerized)
- License
- GPL-3.0
- Runs locally
- No — requires a network request
- Verification
- Not yet verified
- Input
- Query
- Output
- Text
Built with mailcow/mailcow-dockerized. OpenToolVault provides the discovery and browser interface while crediting the original project maintainers.
- Built with
- License
- GPL-3.0
Open-source project
OpenToolVault is an independent directory. We are not affiliated with or endorsed by this project.
References
- / — GitHub Repository
Upstream project · GitHub
- GPL-3.0 License
Upstream project
Frequently asked
What is the primary use case for Mailcow?
Mailcow is primarily used for self-hosting email servers, enabling organizations to manage their email infrastructure securely and independently. It is ideal for businesses, educational institutions, and developers needing control over email routing, spam filtering, and domain management without relying on third-party services.
How does Mailcow handle spam and malware filtering?
Mailcow integrates Rspamd, a powerful spam and malware filtering engine that uses machine learning and rule-based detection. It analyzes email content, headers, and attachments to identify threats. Recent updates (e.g., Rspamd 4.1.4) address vulnerabilities and improve detection rates, ensuring robust protection against evolving email threats.
How do I set up a new email domain with Mailcow?
After deploying Mailcow, log in to the web interface at `http://<server-ip>:80`. Navigate to the 'Domains' section, click 'Add Domain,' and enter the domain name. Configure DNS records (MX, SPF, DKIM) to point to your server's IP. Set mailbox quotas and user permissions through the interface, then verify the domain's functionality with a test email.
How does Mailcow compare to alternatives like PostfixAdmin or Mailgun?
Unlike PostfixAdmin, which is a web-based frontend for Postfix, Mailcow provides a complete stack with integrated spam filtering (Rspamd) and Docker-based scalability. Mailgun, a commercial service, offers ease of use but lacks full control over email infrastructure. Mailcow is better suited for users prioritizing customization and security over convenience.
What should I do if Docker containers fail to start?
Check Docker logs using `docker-compose logs` to identify errors. Common issues include misconfigured environment variables, port conflicts, or missing dependencies. Verify that your server meets hardware requirements (e.g., 2GB RAM). If updates caused the issue, revert to a previous version via the GitHub repository or apply fixes from the latest changelog.