Courier MTA

Self-Hosted

Lightweight, secure open-source Mail Transfer Agent

Overview

Courier MTA is a lightweight, high-performance open-source Mail Transfer Agent (MTA) for reliable email routing and delivery. It supports SMTP/ESMTP, TLS encryption, SASL authentication, and security features like SPF/DKIM. Easy to configure via text files, it integrates seamlessly with Courier’s IMAP/POP3 servers for a full email stack. Deployable via Docker or package managers (Debian, Ubuntu, RHEL), it’s ideal for small/medium businesses or self-hosted setups needing low-resource, secure email handling.

Self-Hosting Resources

Find Official Image on Docker Hub View Source & Docs

Below is a reference structure for docker-compose.yml. ⚠️ Do NOT run blindly. Replace placeholders with official values.

docker-compose.template.yml TEMPLATE


version: '3'
services:
  courier_mta:
    image: <OFFICIAL_IMAGE_NAME>:latest
    container_name: courier-mta
    ports:
      - "8080:<APP_INTERNAL_PORT>"
    volumes:
      - ./data:/app/data
    restart: unless-stopped

Key Features

Lightweight & high-performance email delivery
TLS encryption + SASL authentication support
Built-in SPF/DKIM anti-spam & security tools
Seamless integration with Courier email suite
Flexible deployment (Docker, packages, source)

Frequently Asked Questions

? Is Courier MTA hard to install?

Courier MTA is easy to install via package managers (Debian/Ubuntu/RHEL) or Docker containers. Configuration uses straightforward text files, and comprehensive documentation guides setup—accessible for users with basic server admin experience.

? Is it a good alternative to Postfix?

Yes—Courier MTA is a lightweight alternative to Postfix with similar core MTA functionality but lower resource usage. It shines in simplicity and integration with the Courier email suite, though Postfix has a larger community and more third-party integrations.

? Is it completely free?

Courier MTA is 100% free and open-source under the GNU GPL. There are no paid tiers or hidden costs—you can use, modify, and distribute it without restrictions.

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Tool Info

Pricing Free/Open Source

Category Communication - Email - Mail Transfer Agents

Platform Self-Hosted

Pros

⊕ Privacy-focused (self-hosted control)
⊕ Low resource consumption
⊕ Strong security out-of-the-box
⊕ Simple text-based configuration

Cons

⊖ Requires basic server administration skills
⊖ Limited graphical interface (CLI/text config)
⊖ Smaller community than mainstream MTAs like Postfix