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.

A SaaS product sends on behalf of its customers, so the deciding factors are tenant isolation, whether suppressions can be scoped rather than global, and whether support can answer why one specific account did not receive one specific email. Lifecycle automation and transactional sending usually need to coexist.

Against trial expiry notices, dunning, onboarding sequences, and per-tenant transactional mail, Postal covers multi-tenant support, event stream, the suppressions API, and webhook coverage, and does not cover scheduling. Whether that gap matters depends on how central those are to the build.

• Multi-tenant: Yes
• Event stream: Yes
• Suppressions API: Yes
• Operating since: Not published
• Scheduling: No
• Best published rate per 1,000: Tiers not published in comparable form
• Deliverability: You own it. Reputation depends on your IP, warmup discipline, and authentication.
• Webhooks: Yes
• 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.