Postal

Open-source · self-hostable · replaces 1 SaaS tool on os-alt

postalserver/postal · alive · ★ 16.5k · last commit today · 78 open issues

License: MIT

Good fit for Teams sending real-volume transactional email that want a SendGrid-shaped HTTP API + a clear deliverability dashboard.

Weak at Marketing automation (templates, A/B, drip campaigns) is not Postal's job — pair with Listmonk or Mautic for that.

In a terminal? npx -y github:SolvoHQ/os-alt-cli sendgrid prints the SendGrid comparison table including Postal. how the CLI works →

Replaces these SaaS

SendGrid · Transactional email API
Stand up Postal, create an organization + mail server, generate API credentials. In your application, swap `POST https://api.sendgrid.com/v3/mail/send` for `POST https://postal.example.com/api/v1/send/message` with Postal's `X-Server-API-Key` header. Postal accepts a SendGrid-shaped JSON body with minor field renames (`personalizations[].to[].email` → `to`, `from.email` → `from`).

README badges for the SaaS this replaces

Maintainers and forks: drop a badge in your README to link readers from the SaaS-comparison page back to your repo.

/sendgrid/

FAQ

Is Postal actively maintained?

Yes — last commit today. The repository is alive (commit activity within the past 90 days).

What does Postal cost to self-host?

Postal is free and open source under MIT. Typical self-host VPS cost: $5-10 VPS for the server itself; deliverability matters more than cost — most setups relay through Amazon SES at $0.10 / 1k emails to keep IP reputation clean.

Which SaaS does Postal replace?

Postal is listed as an open-source self-host alternative to: SendGrid.