Postal vs SendGrid

Self-host swap-in for SendGrid. · Self-host SendGrid · Postal on os-alt

Postal is one of the open-source self-host replacements for SendGrid — license MIT, 30min docker-compose (Postal + MariaDB + RabbitMQ) to stand up, and $5-10 vps for the server itself; deliverability matters more than cost — most setups relay through amazon ses at $0. Compare against SendGrid's Free 100/day; Essentials $19.95/mo for 50k; pricing climbs with sender reputation features below.

	Postalopen-source	SendGridpaid SaaS
Category	Transactional email API	Transactional email API
License / pricing	`MIT`	Free 100/day; Essentials $19.95/mo for 50k; pricing climbs with sender reputation features
Starting price	$0 self-host	$19.95/user/mo
GitHub	postalserver/postal ★ 16.5k · last commit todayalive	closed source
Setup time	30min docker-compose (Postal + MariaDB + RabbitMQ)	SaaS — sign up + bill
Monthly 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.	from $19.95/user/mo (Free 100/day; Essentials $19.95/mo for 50k; pricing climbs with sender reputation features)

Switching from SendGrid to Postal

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`).

Full step-by-step migration guide →

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.

Other open-source self-host alternatives to SendGrid

Cuttlefish
AGPL-3.030min docker-compose (Rails app + Postgres)$10 VPS — Rails + Postgres + a sender process; you still want an upstream relay for deliverability.
Haraka
MIT1h (Haraka is a framework — you wire plugins for your routing rules)$5 VPS; you compose Haraka with your own Node plugins, so cost is whatever you build.

In a terminal? npx os-alt sendgrid prints SendGrid's self-host options — how the CLI works →

FAQ

Is Postal a free alternative to SendGrid?

Yes — Postal is open source under MIT. Self-host 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.. SendGrid starts at $19.95/user/mo (Free 100/day; Essentials $19.95/mo for 50k; pricing climbs with sender reputation features).

How long does Postal take to set up vs SendGrid?

Self-hosting Postal: 30min docker-compose (Postal + MariaDB + RabbitMQ). SendGrid is a hosted SaaS — sign up and you're in.

What is Postal good at, and what is it weak at?

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..