haraka/Haraka

Health v2 · maintenance only

Adoption not part of the score

5613 stars · 712 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

Haraka is a fast, highly extensible, event-driven SMTP server written in Node.js with a modular plugin architecture. It is widely deployed as a filtering MTA or MSA, handling thousands of concurrent connections with built-in outbound delivery and strong spam protection.

Use cases

• run a high-performance SMTP server in Node.js
• filter spam before forwarding mail to an IMAP backend
• build a custom mail transfer agent with JavaScript plugins
• accept authenticated mail submission on port 465 or 587
• add DKIM signing and SPF validation to email delivery
• rewrite recipient addresses before relaying to Exchange
• handle thousands of concurrent SMTP connections

When to choose

• you need a scalable SMTP server or filtering MTA you can extend in JavaScript
• you want spam protection via plugins like SpamAssassin, rspamd, DNSBLs, or ClamAV
• you need an MSA with auth and DKIM for outbound mail submission
• you want hook-based customization of SMTP transactions without forking an MTA

When to avoid

• you need a full mail store, IMAP server, or local delivery agent
• you want a turnkey mail server with a web admin UI and no coding
• your stack is not JavaScript/Node.js and you prefer a traditional MTA like Postfix or Exim

Facets

service · maturity stable

http-server middleware plugin-system security email email backend self-hosted security developer-tools cross-platform self-hosted smtp-server mta mail-transfer-agent spam-filtering dkim spf email-server mail-server nodejs linux macos

Member repositories

For agents

markdown · JSON · MCP: product_card(name="haraka/Haraka")