Haraka
High-performance, extensible SMTP server built on Node.js
Haraka is an open source, event-driven SMTP server written in Node.js. It is designed for high throughput and concurrency, and is commonly deployed as a filtering MTA or mail submission agent (MSA) via a flexible plugin system.
Key Features
- Modular plugin architecture to customize SMTP behavior and mail processing
- High-performance asynchronous design suitable for thousands of concurrent connections
- Built-in outbound delivery and queueing for authenticated/relayed messages
- Supports common email authentication and policy needs via plugins (for example DKIM and SPF)
- Useful as a filtering layer alongside a separate mail store and IMAP server
Use Cases
- Run a high-throughput SMTP front-end with custom filtering and routing rules
- Deploy an MSA on port 587 with authentication and outbound signing policies
- Add specialized anti-spam and validation logic in front of an existing mail system
Haraka is a strong fit when you want a programmable SMTP server that is easy to extend in JavaScript and integrates with existing mail storage and IMAP solutions. Its plugin ecosystem enables practical customization without modifying the core server.
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Tech Stack:
JavaScript
npm
Node.jsSimilar Services
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