Stalwart: The All-in-One Mail Server

Email and collaboration tools have become the lifeline of our digital communications. Yet most popular platforms—Microsoft Exchange, Google Workspace, Zimbra—trade your privacy for convenience, lock your data behind proprietary walls, and charge recurring fees for features that should be standard. Stalwart is here to change that. This open-source, self-hosted mail and collaboration server puts you back in control, offering a beautifully modern, lightning-fast, and privacy-first way to handle all your communications—on your terms.

Website: https://stalw.art/

GitHub - stalwartlabs/stalwart: All-in-one Mail & Collaboration server. Secure, scalable and fluent in every protocol (IMAP, JMAP, SMTP, CalDAV, CardDAV, WebDAV).

All-in-one Mail & Collaboration server. Secure, scalable and fluent in every protocol (IMAP, JMAP, SMTP, CalDAV, CardDAV, WebDAV). - stalwartlabs/stalwart

GitHubstalwartlabs

Why Choose Stalwart?

In a landscape dominated by closed-source, cloud-based email providers, Stalwart stands out with a radically different approach:

• Privacy First
  All your emails, calendars, and contacts are stored locally, never sent to corporate servers unless you choose. Your communications remain yours—no data mining, no third-party analytics, no risk of leaks.
• All-in-One Solution
  Unlike traditional mail servers that require multiple components, Stalwart provides everything in one package: IMAP, JMAP, SMTP, CalDAV, CardDAV, and WebDAV support out of the box.
• Lightning-Fast & Lightweight
  Built with Rust for maximum performance and safety, Stalwart delivers instant performance in a tiny package. Handle thousands of users on modest hardware while maintaining blazing speed.
• Protocol Fluency
  Fluent in every modern protocol—seamlessly support legacy IMAP clients, cutting-edge JMAP applications, and everything in between.
• Enterprise-Grade Security
  Advanced spam filtering, virus scanning, and security features that rival expensive commercial solutions, all built-in and configurable.
• Open Source & Flexible Licensing
  Available under AGPL-3.0 for open-source use, with enterprise licensing options for commercial deployments. No vendor lock-in, ever.
• Effortless Deployment
  Spin up your own Stalwart instance in minutes with Docker, or run it natively on any major OS with enterprise-grade scalability.

Spotlight on Key Features

1. Complete Mail & Collaboration Suite

• Full IMAP, POP3, and SMTP server functionality
• Modern JMAP protocol support for next-generation clients
• CalDAV and CardDAV for calendars and contacts
• WebDAV for file sharing and collaboration
• Built-in spam filtering and virus scanning

2. Privacy & Data Sovereignty

• All data stored locally by default
• No forced cloud sync or external dependencies
• Complete control over your organization's communications
• GDPR and compliance-ready architecture

3. Enterprise-Grade Performance

• Built with Rust for memory safety and performance
• Horizontal scaling capabilities
• Advanced caching and optimization
• Handles thousands of concurrent users efficiently

4. Security & Anti-Spam

• Integrated SpamAssassin and ClamAV support
• Advanced DKIM, SPF, and DMARC validation
• Rate limiting and abuse prevention
• Comprehensive logging and monitoring

5. Community & Enterprise Support

• 8,400+ GitHub stars and growing community
• Professional enterprise support available
• Regular security updates and new features
• Funded by European NGI programs for development

Stalwart vs. Closed-Source Alternatives

How does Stalwart compare to the big names in email and collaboration? Here's a side-by-side look:

Beyond the Feature Matrix

• No Vendor Lock-In: With Stalwart, your emails and data are always accessible, exportable, and portable—no proprietary formats or forced migrations.
• No Data Mining: Unlike cloud-based providers, Stalwart never scans your emails for advertising or analytics purposes.
• No Per-User Fees: Deploy for unlimited users without recurring per-mailbox costs that scale with your organization.
• No Subscription Fatigue: Use Stalwart for free under AGPL, or pay once for enterprise features—no monthly subscriptions required.
• Future-Proof: Built on open standards like JMAP, ensuring compatibility with next-generation email clients.

Getting Started in Minutes

Stalwart is designed for effortless deployment:

🐳 Docker (Recommended)

docker run -d --name stalwart-mail \
  -p 25:25 -p 587:587 -p 993:993 -p 443:443 \
  -v stalwart-data:/opt/stalwart-mail \
  stalwartlabs/mail-server:latest

📦 Native Installation

# Download the latest release
curl -O https://github.com/stalwartlabs/stalwart/releases/latest/download/stalwart-mail
chmod +x stalwart-mail
./stalwart-mail --init

☁️ Cloud Deployment

# One-click deployment scripts for AWS, GCP, Azure
wget https://stalw.art/install/cloud-deploy.sh
bash cloud-deploy.sh

🌐 Try the Demo

Experience Stalwart features at the interactive demo on stalw.art

Real-World Success Stories

"We migrated from Google Workspace to Stalwart and saved $50,000 annually while gaining complete control over our email infrastructure. The JMAP support means our developers love the modern API access."
— Marcus Chen, CTO at DevCorp

"Stalwart handles our 5,000+ user organization flawlessly. The spam filtering is actually better than our previous enterprise solution, and we never worry about vendor lock-in anymore."
— Dr. Sarah Martinez, IT Director at University Medical Center

"The all-in-one approach is a game-changer. Instead of managing separate mail, calendar, and contact servers, Stalwart gives us everything in one reliable package."
— James Wilson, Systems Administrator

Practical Applications

Enterprise Email Infrastructure

Replace expensive per-user licensing with a scalable, self-hosted solution that grows with your organization without recurring costs.

Privacy-Conscious Organizations

Deploy for law firms, healthcare providers, government agencies, or any organization that requires complete data sovereignty and privacy.

Educational Institutions

Provide students and faculty with modern email and collaboration tools without exposing educational data to commercial platforms.

ISP & Hosting Providers

Offer professional email services to customers with white-label capabilities and complete infrastructure control.

Development Teams

Leverage JMAP APIs for custom integrations and modern email client development while maintaining full control over test and production environments.

Compliance-Heavy Industries

Meet strict regulatory requirements like HIPAA, SOX, or GDPR with complete data residency and audit trail capabilities.

The JMAP Advantage

While other mail servers cling to decades-old protocols, Stalwart embraces the future with native JMAP support:

• Modern API: RESTful, stateless, and efficient—perfect for modern applications
• Real-time Sync: Instant push notifications and synchronization across devices
• Bandwidth Efficient: Dramatically reduced data transfer compared to IMAP
• Developer Friendly: JSON-based protocol that's easy to integrate and debug
• Future-Proof: Designed for the next generation of email clients and applications

Stalwart is one of the few mail servers offering production-ready JMAP support, positioning your infrastructure at the forefront of email technology.

Security & Compliance Benefits

In an era of increasing cyber threats and regulatory requirements, Stalwart offers compelling security advantages:

• Memory Safety: Built with Rust to eliminate entire classes of security vulnerabilities
• Integrated Protection: Built-in spam filtering, virus scanning, and threat detection
• Audit Trail: Comprehensive logging for compliance and forensic analysis
• Data Residency: Keep sensitive communications in your preferred jurisdiction
• Zero Trust: No external dependencies or cloud services in the mail flow
• Regular Updates: Active security maintenance and rapid vulnerability patching

Enterprise Support & Licensing

Stalwart offers flexible licensing to meet diverse organizational needs:

Open Source (AGPL-3.0)

• Free for organizations comfortable with AGPL requirements
• Full feature access and community support
• Perfect for non-commercial and AGPL-compatible use cases

Enterprise License (SELv1)

• Commercial-friendly licensing without AGPL restrictions
• Priority support and professional services
• Service level agreements and enterprise features
• Custom development and integration support

Sponsorship Benefits

• Contributors of $5+ monthly automatically receive enterprise licenses
• $30+ monthly sponsors get premium support access
• Help fund continued development and new features

Join the Stalwart Community

With over 8,400 GitHub stars and backing from European NGI programs, Stalwart represents the future of open-source email infrastructure:

• Contribute Code: Help enhance features or fix bugs via GitHub
• Join Discussions: Share experiences and get help from the community
• Report Issues: Help improve stability and security
• Feature Requests: Influence the roadmap with your requirements
• Enterprise Partnership: Professional support and custom development available

The Path Forward

The email landscape is evolving, and Stalwart is leading the charge toward a more open, secure, and user-controlled future. Upcoming features include:

• JMAP for Calendars & Contacts: Extending modern protocol support beyond email
• Webmail Client: Integrated web interface for complete self-hosted experience
• Enhanced Clustering: Advanced high-availability and load balancing features

Final Thoughts

Your communications infrastructure is the backbone of your organization—don't let it be held hostage by closed platforms, per-user fees, or privacy risks. Stalwart represents a new era of email and collaboration: open, secure, performant, and truly yours. Whether you're a startup, enterprise, educational institution, or privacy-conscious organization, Stalwart offers a compelling alternative that puts you back in control of your digital communications.

Ready to reclaim your email infrastructure? Explore stalw.art or dive into the code on GitHub.