Cuttlefish
Open-source transactional email server with a web UI.
Cuttlefish is a self-hosted transactional email server with SMTP delivery, bounce handling, open and click tracking, real-time analytics, a web UI, and an API. It runs on top of Postfix and is explicitly positioned as free and open source software.
Growth work lives or dies on targeting and measurement. What matters is whether behavioral triggers can be built without engineering time, whether the event stream supports attribution past the open, and whether deliverability holds when broadcast volume shares a reputation with product email.
Against behavior-triggered journeys, broadcasts, and winback campaigns measured on revenue, Cuttlefish covers event stream, the suppressions API, and multi-tenant support, and does not cover scheduling. Whether that gap matters depends on how central those are to the build.
- Scheduling: No
- Event stream: Yes
- Deliverability: Self-hosted deliverability depends on Postfix configuration, IP reputation, DNS authentication, bounce processing, and list hygiene. Cuttlefish adds bounce suppression and analytics around SMTP delivery.
- Operating since: Not published
- Suppressions API: Yes
- Best published rate per 1,000: Tiers not published in comparable form
- Multi-tenant: Yes
- Free tier: Free self-hosted, open source
- Starts at: Free self-hosted
Self-hosted deliverability depends on Postfix configuration, IP reputation, DNS authentication, bounce processing, and list hygiene. Cuttlefish adds bounce suppression and analytics around SMTP delivery.
Teams that want a self-hosted transactional email dashboard in front of Postfix.
Teams that need managed deliverability, inbound parsing, or template tooling.
- › Open-source transactional email with a useful web UI
- › SMTP integration works with any framework or language
- › Bounce handling, open tracking, click tracking, and application-level analytics are built in
- › Project site describes the product as beta
- › Official site says it does not handle incoming email or built-in templates
- › Requires Postfix and self-hosted operations expertise
Features at a glance
| API | Yes |
| SMTP | Yes |
| SDKs | None |
| Webhooks | No |
| Templates | none |
| React Email | No |
| Batch send | No |
| Scheduled send | No |
| Suppressions | Yes |
| Multi-tenant | Yes |
| Inbound parsing | No |
| Event stream | Yes |
| Idempotency keys | No |
| Dedicated IP | No |