docker-mailserver/docker-mailserver
Docker Mailserver
This project provides a full-stack, containerized mail server platform designed for self-hosting. It functions as a complete mail transfer agent that bundles essential services—including SMTP, IMAP, and POP3—into a unified environment. By leveraging container orchestration, it enables the deployment of private email infrastructure that handles message transport, delivery, and user management within a single, manageable service.
The platform distinguishes itself through deep integration with container runtimes and robust configuration flexibility. It supports granular customization via configuration-file injection, initialization-script hooking, and volume-based persistence, allowing administrators to tune mail transport parameters and maintain state across container lifecycles. It also offers advanced operational capabilities such as multi-tenant relay routing, automated container updates, and native support for Kubernetes environments.
Beyond core delivery, the server includes a comprehensive security and filtering suite. It integrates modular middleware for real-time spam and malware analysis, enforces cryptographic signing for message authenticity, and provides automated protection against brute-force attacks and malicious traffic. Administrative tasks are simplified through a dedicated command-line utility for account management, alias configuration, and storage quota enforcement, alongside built-in observability tools for monitoring server health and filtering statistics.
The project is distributed as a container image, with documentation and configuration patterns provided to support deployment across standard container runtimes and orchestration platforms.
Features
- Mail Servers - Provides a complete mail transfer agent and delivery system within a containerized environment.
- Self-Hosted Infrastructure - Enables private, full-stack email hosting with support for standard protocols and secure delivery.
- Persistent Storage Volumes - Mounts dedicated storage volumes to ensure email data remains available outside the container after restarts.
- Email Filtering - Applies custom rules globally or per-user to automatically sort, redirect, or discard messages.
- Email Signing - Signs and verifies email messages using cryptographic standards like DKIM.
- Kubernetes Orchestration - Orchestrates mail services within clusters using standard manifests for configuration and storage.
- Server Configuration Management - Simplifies management of accounts, aliases, and system parameters via a dedicated command-line utility.
- Directory Service Integrations - Integrates with external LDAP and identity providers to centralize user authentication.
- Mail Transmission Security - Enforces encrypted mail delivery protocols to protect data in transit.
- Backend Security Middleware - Integrates modular scanning and filtering engines into the mail delivery pipeline for spam and malware analysis.
- User Account Management - Provides command-line tools for creating, deleting, and securing email accounts.
- User Authentication Strategies - Authenticates users against local or external providers to control access.
- Email Services - Full-stack mail server suite containerized for easy deployment.
- Email Solutions - Listed in the “Email Solutions” section of the Awesome Selfhosted awesome list.
- Configuration Persistence - Maps external directories to internal paths to ensure mail server settings persist across container lifecycles.
- Persistent Storage Management - Enforces global limits on mailbox sizes and configures storage formats for managed mail data.
- Persistent Volume Mapping - Maps internal application directories to host storage to ensure mail data and configuration persistence.
- Container Orchestration Management - Bundles multiple independent mail services into a single container environment with unified supervision.
- Mail Delivery Agents - Supports multi-tenant relay routing and sender-dependent gateways for complex delivery requirements.
- Alias Management - Redirects incoming mail for specific addresses to local accounts or external destinations using static mappings or regular expressions.
- State Persistence - Maintains persistent storage for filtering data and learned patterns to ensure consistent performance.
- Automated Container Updaters - Monitors and automatically updates container images to ensure the mail server runs the latest version.
- IMAP Services - Provides secure access for email clients to fetch messages using encrypted IMAP connections.
- Mail Protocol Implementations - Operates standard network services for sending, receiving, and retrieving messages.
- Outbound Mail Relays - Delegates the delivery of outgoing emails to external services or relay hosts.
- Sub-addressing Extensions - Automatically organizes incoming messages into folders by parsing tags from recipient addresses.
- Brute Force Protections - Protects against brute-force attacks by monitoring logs and blocking suspicious IP addresses.
- Identity Federation Providers - Validates user credentials against external identity providers using tokens for centralized access control.
- Message Encryption - Encrypts stored email messages at rest to ensure data privacy.
- Server Administration - Provides administrative commands against running containers to simplify configuration and maintenance.
- Usage Quota Managers - Enforces disk usage limits on individual mailboxes to prevent system-wide storage exhaustion.
- Shell Script Execution Engines - Executes user-defined shell scripts during container startup to patch configurations before services initialize.
- Sender Identity Verifications - Restricts users to sending mail only from authorized addresses to prevent spoofing.
- Email Forwarding Rules - Redirects incoming messages to external addresses using alias rules instead of local storage.
- Mail Routing Policies - Processes outgoing mail from local users and accepts incoming mail from third-party servers.
- Proxy-Aware Routing - Supports reverse proxy configurations and header preservation to maintain accurate client IP visibility.
- Relay Server Configurations - Routes outbound mail through specific relay hosts based on the sender domain.
- Administrative Account Management - Provides master account access for administrative maintenance and mailbox management tasks.
- Authentication Security Policies - Defines security policies for handling incoming mail that fails authentication checks.
- YAML Configuration Files - Allows granular tuning of mail transport parameters by mounting external configuration files.
- Automated Server Maintenance - Manages background services including log rotation, update checks, and automated mail retrieval.
- Real-Time Monitoring Dashboards - Exposes a web-based dashboard for viewing real-time filtering data and security statistics.
- System Services - Ensures mail server containers automatically start at boot and remain active as persistent system services.
