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Cuttlefish

Transactional email server with click and open tracking

Mail Servers ★ 1.6k stars Medium setup AGPL-3.0

Cuttlefish is a self-hosted transactional email server that sends application email and tracks deliveries, opens, and clicks. It provides a dashboard for monitoring email performance.

Official siteSource code

Key features

  • Transactional email delivery
  • Open and click tracking
  • Delivery monitoring dashboard
  • SMTP relay interface

Pros & cons

Strengths

  • Released under the AGPL-3.0 license
  • First-class Docker support for quick deployment
  • Active community (1.6k GitHub stars)
  • Written in Ruby

Trade-offs

  • Outbound mail only
  • Slower development

Is Cuttlefish secure?

OSV.dev has no published security advisories for Cuttlefish's repository. No known vulnerabilities is not proof of security: it means none have been publicly catalogued.

Source: OSV.dev, checked 2026-10-14. How this is measured.

Cuttlefish replaces

Self-hosted Mailgun alternativesSelf-hosted SendGrid alternativesSelf-hosted Postmark alternatives

Health badge

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SelfHostIndex: 19 · at risk

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   :alt: SelfHostIndex health score for Cuttlefish
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The score is recomputed on every nightly rebuild from public repository data — see how it is calculated.

Compare Cuttlefish

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