Apache James

Apache James (Java Apache Mail Enterprise Server) is a modular, open-source mail server platform written in Java. It provides a complete, secure, and extensible solution for handling email services, including sending, receiving, storing, and filtering messages. Designed for flexibility and scalability, James supports both standalone and distributed deployments, making it suitable for personal, enterprise, and cloud-based email infrastructures.

Features

• Modular architecture with pluggable components
• Support for standard email protocols: SMTP, LMTP, POP3, IMAP, ManageSieve, and JMAP
• Mailet container for custom email processing logic
• Storage APIs for mailbox, user, and search operations
• Multiple storage backends: Cassandra, PostgreSQL, MySQL, HSQLDB, OpenSearch, and S3
• Administration via JMX, REST, and command-line interfaces
• MIME parsing, DKIM signing/verification, SPF, and Sieve filtering support
• Docker-ready images and deployment guides

Capabilities

• Acts as a Mail Transfer Agent (MTA), Mail Delivery Agent (MDA), and Mail User Agent (MUA)
• Enables custom routing, filtering, and transformation of emails through Mailets
• Provides full-text search and indexing of emails
• Supports distributed mail server architecture for horizontal scalability
• Integrates with external systems via REST APIs and message queues
• Offers secure communication with TLS/SSL and authentication mechanisms
• Extensible through internal and external projects like Mime4J, jSieve, jSPF, and jDKIM

Benefits

• Highly customizable to fit specific email processing needs
• Scales from small installations to large, distributed environments
• Reduces operational complexity with modular design and Docker support
• Enhances security and compliance with built-in cryptographic tools
• Promotes open standards and interoperability
• Backed by an active open-source community and Apache governance