Über Stalwart
Stalwart is an open-source mail & collaboration server with JMAP, IMAP4, POP3, SMTP, CalDAV, CardDAV and WebDAV support and a wide range of modern features. It is written in Rust and designed to be secure, fast, robust and scalable.
Features
All-in-One Platform
- Comprehensive email and collaboration tools in a single binary
- Built in Rust for memory safety and performance
- Unified configuration across all components
- JMAP, IMAP, SMTP, CalDAV, CardDAV, and WebDAV support
Enhanced Security
- Encryption at rest with S/MIME and OpenPGP
- Strong transport security via DANE, MTA-STS, and TLS Reporting
- Automatic TLS certificate provisioning with ACME
- Granular access controls, rate limiting, and fail2ban protection
- Security-audited codebase
Advanced Spam & Phishing Protection
- Built-in DMARC, DKIM, SPF, and ARC authentication
- Statistical spam classifier with automatic training
- DNS Blocklists for IPs, domains, and content hashes
- Phishing protection against homographic and spoofing attacks
- Sender reputation monitoring and greylisting
Highly Flexible
- Enhanced Sieve scripting capabilities
- Dynamic configuration rules
- Full-text search across 17 languages
- Multiple storage and authentication backend options
- Web-based interface with self-service portal
Built to Scale
- Seamless load balancing and fault tolerance
- Node autodiscovery for easy network expansion
- Partition-tolerant failure detection
- Simplified architecture without coordinators or proxies
Unified Collaboration
- Calendar and event scheduling with free/busy support
- Rich contact management
- File storage and secure sharing
- Real-time syncing across devices