Apache James
The modular, cloud-native enterprise mail server for high-performance messaging and data sovereignty.

The premier open-source, Docker-native mail server distribution for privacy-conscious organizations.
Mailu is a feature-complete, modular mail server distribution designed for seamless containerized deployment via Docker and Docker Compose. As of 2026, Mailu has solidified its position as the leading open-source alternative to proprietary suites like Microsoft 365 or Google Workspace for organizations demanding total data sovereignty. Its architecture is built on a microservices model, orchestrating industry-standard components including Postfix (MTA), Dovecot (IMAP/POP3), Rspamd (Filtering), and Nginx (Web Frontend). The system is designed to be low-maintenance, providing a web-based administration interface that handles complex configurations such as DKIM signing, DMARC policies, and SSL/TLS certificate management through Let's Encrypt. Technical architects favor Mailu for its small resource footprint and its ability to scale storage independently of the application logic. It supports multiple webmail frontends like Roundcube and SnappyMail, and includes advanced features such as aliasing, domain delegation, and a RESTful API for automated user provisioning. In a landscape increasingly concerned with GDPR compliance and data residency, Mailu provides a robust, audited framework for secure communication without the overhead of legacy mail server management.
Advanced filtering system using fuzzy hashes, regex, and statistical analysis to block spam/malware.
The modular, cloud-native enterprise mail server for high-performance messaging and data sovereignty.
A high-scale, AI-optimized cloud email service designed for high deliverability and programmatic flexibility.
The open-source mail hosting and management platform for high-performance self-sovereignty.
Enterprise-grade SMTP relay and email delivery engine for high-volume senders.
Verified feedback from the global deployment network.
Post queries, share implementation strategies, and help other users.
Built-in Certbot integration for automated Let's Encrypt certificate issuance and renewal.
Allows administrative rights to be delegated to specific users for specific domains.
Integrated capability to pull emails from external POP3/IMAP accounts into Mailu mailboxes.
Supports Roundcube, SnappyMail, and Rainloop as plug-and-play container modules.
Ability to route outbound mail through a third-party SMTP relay (like SendGrid or AWS SES).
Dovecot-based storage backend that supports local filesystem, NFS, or S3-compatible storage via fuse mounts.
Companies needing to keep internal communications off third-party servers to protect IP.
Registry Updated:2/7/2026
Eliminating high monthly costs from providers like Mailgun or Postmark for high-volume apps.
Service providers hosting mail for hundreds of small business clients.