Stalwart is an Open-source Self-hosted Mail Server

Stalwart Mail Server is an open-source, self-hosted email server solution designed to be robust, secure, and easy to manage. It aims to provide a comprehensive set of features for handling email with minimal configuration, making it a great choice for small businesses, developers, and tech enthusiasts.

Key Features

• Complete Email Solution: Includes SMTP, IMAP, and POP3 services.
• Security: Built-in support for TLS/SSL, DKIM, SPF, and DMARC.
• Web-Based Management: User-friendly interface for managing email accounts and server settings.
• Spam and Virus Protection: Integrates with SpamAssassin and ClamAV.
• Multi-Domain Support: Host multiple domains on a single server.
• Extensibility: API support for custom integrations.

Other Features

JMAP Server

• JMAP Core and Mail: Full compliance with JMAP standards.
• JMAP for Sieve Scripts: Manage Sieve scripts with JMAP.
• JMAP Extensions: Includes JMAP for WebSocket, Blob Management, and Quotas.

IMAP4, POP3, and ManageSieve Server

• IMAP4rev2 and IMAP4rev1: Supports numerous extensions.
• POP3 Server: Includes extensions, STLS, and SASL support.
• ManageSieve Server: Manage Sieve scripts efficiently.

SMTP Server

• Message Authentication: Built-in DMARC, DKIM, SPF, and ARC support.
• Transport Security: Supports DANE, MTA-STS, and SMTP TLS reporting.
• Inbound Throttling and Filtering: Granular configuration rules, sieve scripting, MTA hooks, and milter integration.
• Distributed Virtual Queues: Features delayed delivery, priority delivery, quotas, routing rules, and throttling support.
• Envelope Rewriting and Message Modification: Flexible handling of message envelopes and modifications.

Spam and Phishing Filter

• Filtering Rules: Comprehensive set on par with popular solutions.
• Spam Classifier: Automatic training capabilities.
• DNS Blocklists: Checks IP addresses, domains, and hashes.
• Collaborative Filtering: Uses Pyzor for spam filtering.
• Phishing Protection: Against homographic URL attacks, sender spoofing, and more.
• Trusted Reply Tracking: Recognizes and prioritizes genuine replies.
• Sender Reputation Monitoring: By IP address, ASN, domain, and email address.
• Greylisting: Temporarily defers unknown senders.
• Spam Traps: Analyzes spam through decoy email addresses.

Flexibility and Scalability

• Pluggable Storage Backends: Supports RocksDB, FoundationDB, PostgreSQL, MySQL, SQLite, S3-Compatible, Redis, and ElasticSearch.
• Clustering Support: Node autodiscovery and partition-tolerant failure detection.
• Authentication Backends: Built-in, LDAP, or SQL support.
• Full-Text Search: Available in 17 languages.
• Sieve Scripting: Supports all registered extensions.
• Email Aliases and Mailing Lists: Includes subaddressing and catch-all addresses support.
• Automatic Account Configuration: Uses autoconfig and autodiscover.
• OpenTelemetry Integration: Enables monitoring, tracing, and performance analysis.
• Webhooks: For event-driven automation.
• Disk Quotas: Manage storage efficiently.

Web-Based Administration

• Comprehensive Management: Account, domain, group, and mailing list management.
• SMTP Queue Management: Handles messages and outbound DMARC and TLS reports.
• Report Visualization: Interface for DMARC, TLS-RPT, and Failure (ARF) reports.
• Configuration Management: Configure every aspect of the mail server.
• Log Viewer: Search and filter capabilities.
• Self-Service Portal: For password reset and encryption-at-rest key management.

Security and Robustness

• Encryption at Rest: S/MIME or OpenPGP.
• TLS Certificate Provisioning: Automatic with ACME using various challenges.
• OAuth 2.0: Authorization code and device authorization flows.
• Two-Factor Authentication: Time-based One-Time Passwords (2FA-TOTP).
• App Passwords: For application-specific access.
• Automated Blocking: Of hosts causing multiple authentication errors (fail2ban).
• Access Control Lists (ACLs): Manage permissions and access.
• Rate Limiting: Prevents abuse and overload.
• Security Audited: Read the security report.
• Memory Safe: Thanks to Rust programming language.

Pros and Cons

Pros:

• Open-Source: Free to use and modify.
• Comprehensive Features: Includes everything needed for a full email server.
• Security: Strong focus on security features.
• Ease of Use: Simple installation and management through a web interface.

Cons:

• Resource Intensive: Requires a dedicated server or VPS.
• Configuration Complexity: May require some technical knowledge to set up.
• Maintenance: Requires regular updates and maintenance.

Installation Guide

To install Stalwart Labs Mail Server, follow these steps:

System Requirements:

• A server running Linux (Ubuntu/Debian recommended).
• Minimum 2 GB RAM.
• A domain name and DNS records configured.

Configure Environment:

Edit the .env file with your domain and other settings.

Access the Web Interface:

Open your browser and navigate to http://your-domain.com:8080.

Set Up Email Accounts:

Use the web interface to create and manage email accounts.

Start the Mail Server:

docker-compose up -d

Copy the example environment file:

cp .env.example .env

Clone the Repository:

git clone https://github.com/stalwartlabs/mail-server.git
cd mail-server

Install Dependencies:

sudo apt install docker docker-compose -y

Update System:

sudo apt update && sudo apt upgrade -y

License

Not listed

Conclusion

Stalwart Mail Server offers a robust and secure email server solution suitable for various use cases. Its comprehensive feature set and open-source nature make it an attractive option for those looking to host their own email server.

With a bit of setup, you can have a fully functional mail server up and running, tailored to your specific needs.