Maddy Mail Server

Maddy Mail Server is an open-source, self-hosted mail server that provides a combined implementation of SMTP and IMAP functionality. It operates as a single daemon that handles the sending of messages as a Mail Transfer Agent and the reception of messages as a Mail Exchange server. The software is designed to manage the entire lifecycle of email communication within a single installation.

Users deploy Maddy as a server application to manage the delivery of outgoing mail, the acceptance of incoming mail, and the storage of messages for retrieval via the IMAP protocol. By consolidating these roles, the software removes the need to coordinate multiple separate services to achieve a functioning mail system. It is used primarily on Linux servers where a simplified deployment of email infrastructure is required.

Key features

• SMTP functionality for sending and receiving messages
• Integrated IMAP server for message storage and access
• Built-in DKIM support for email signing
• SPF implementation for sender verification
• DMARC support for domain policy enforcement
• DANE integration for secure certificate validation
• MTA-STS support for encrypted transport requirements
• Single daemon architecture with uniform configuration

The architecture of Maddy focuses on a composable design that integrates auxiliary protocols mandatory for modern email security. By including DKIM, SPF, DMARC, DANE, and MTA-STS within the core daemon, the software ensures that security configurations are handled through a consistent interface. This approach is intended for system administrators who want to minimize the maintenance costs associated with managing several different mail-related binaries and configuration files.

While the SMTP and security components are the primary focus, the software also includes an IMAP storage implementation. This storage component is currently marked as beta, meaning it provides basic message retrieval but may lack the advanced feature set found in dedicated storage agents. The software remains capable of handling the delivery business regardless of the storage backend used.

Maddy Mail Server serves as a complete solution for users hosting their own email infrastructure on a private server.