Postal

Postal is an open-source, self-hosted mail server designed for websites and web servers to manage the delivery of transactional and bulk emails. The software is deployed as a server application that allows users to maintain full control over their email infrastructure and delivery pipelines.

By running on its own server, Postal removes the dependency on third party proprietary platforms for sending outgoing mail and handling incoming messages. It provides a centralized system for managing mail domains and routing, making it suitable for applications that require high volumes of automated communication. The platform is used to send everything from password resets and order confirmations to large scale marketing newsletters.

Key features

• Full mail server functionality for web applications
• Support for transactional email delivery
• Capability to send bulk email campaigns
• SMTP server implementation for outgoing mail
• Management of incoming email streams
• Self-hosted architecture for data privacy
• Web interface for server administration

Built using Ruby, Postal is intended for developers and system administrators who require a dedicated email delivery system. It replaces the need for external API based mail services by providing a local environment to route and monitor mail traffic. The system integrates with existing web servers to automate notifications and system alerts. Because it is self-hosted, it allows for deep customization of mail headers and delivery settings that are often restricted in managed services. This architecture ensures that sensitive communication data remains on the user's own hardware rather than on a third party cloud.

Postal serves as a private infrastructure option for organizations that need to manage high volumes of email while avoiding the costs and constraints of managed delivery services. It is a professional grade tool for those who prefer to own their mail delivery stack.