Postal

Postal is a self-hosted mail server designed as an open-source alternative to SendGrid or Mailgun. Handles outbound and inbound, RESTful API, multi-domain. Operationally heavier than just running Postfix.

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, Postal 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: You own it. Reputation depends on your IP, warmup discipline, and authentication.
• 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
• Starts at: Self-hosted only

You own it. Reputation depends on your IP, warmup discipline, and authentication.

Teams with infra ops capacity that want full control of their mail delivery.