Stalwart Mail Server: Self-Hosted Email and Collaboration Training Course

Overview of Stalwart

• System purpose and architectural objectives
• Architecture based on a single, consolidated Rust binary
• Differentiation from conventional mail infrastructure stacks
• Licensing frameworks: AGPL-3.0 and Enterprise editions

Deployment and Initialization

• System prerequisites and supported operating environments
• Deployment using Docker and Docker Compose containers
• Binary installation procedures for Linux environments
• Selection of compatible database backends
• Bootstrap configuration and initial setup wizard

Protocol Standards and DNS Configuration

• SMTP protocol handling for inbound and outbound mail flow
• Email retrieval via IMAP4 and JMAP protocols
• Support for legacy clients through POP3
• DNS record configuration: MX, SPF, DKIM, and DMARC
• Automated rotation of DKIM signing keys

Security Posture and Identity Management

• TLS encryption with automated ACME certificate issuance
• Transport security protocols: DANE and MTA-STS
• Supported authentication mechanisms: internal, LDAP, OIDC, and SQL
• Implementation of OAuth 2.0 and multi-factor authentication
• Granular access control lists (ACLs) and permission models
• Rate limiting controls and automated threat-based IP blocking

Threat Mitigation and Filtering

• Integrated spam filtering architecture
• Classification driven by artificial intelligence and large language models (LLMs)
• Statistical Bayesian filtering mechanisms
• Integration with DNS blocklists and Pyzor networks
• Greylisting techniques and honeypot deployment
• Protection against phishing and homographic attacks

Data Storage and Retrieval Engines

• Supported storage engines: RocksDB, PostgreSQL, MySQL, and SQLite
• Cloud-based object storage integration via S3 and Azure Blob
• Performance caching through Redis
• Full-text search capabilities: internal vs. external search engines

Collaborative Services

• Scheduling and calendar management via CalDAV and JMAP
• Contact management via CardDAV and JMAP
• File storage capabilities using WebDAV
• Collaborative sharing protocols with ACLs and JMAP Sharing

Tenant Isolation and User Administration

• Logical separation of domains and tenant environments
• User account management and group structuring
• Mailing list distribution and alias configuration
• Subaddressing rules and catch-all address handling
• Enforced disk quotas for individual users and tenant groups

Administrative Tools and Operational Monitoring

• Web-based user interface for system statistics and oversight
• Command-line interface (CLI) for scripting and automation tasks
• Management of SMTP mail queues
• Monitoring via OpenTelemetry traces and Prometheus metrics
• Event-driven automation through webhooks

High Availability and Cluster Architecture

• P2P cluster coordination mechanisms
• Distributed clustering using Kafka and Redis
• Data distribution via read replicas and storage sharding
• Kubernetes-native deployment strategies
• Fault tolerance and resilience design principles

Advanced System Configuration

• Email filtering rules using the Sieve scripting language
• MTA hooks and Milter protocol integration
• Mail routing policies and virtual queue management
• Envelope address rewriting capabilities

Transition and Ecosystem Integration

• Migration pathways from Postfix and Dovecot infrastructure
• Migration support from Microsoft Exchange environments
• Configuration via Autoconfig and Autodiscover standards
• Automated management of DNS dependencies
• Declarative deployment workflows driven by API integration for government and enterprise systems