Cuttlefish vs SendGrid

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

Cuttlefish is one of the open-source self-host replacements for SendGrid — license AGPL-3.0, 30min docker-compose (Rails app + Postgres) to stand up, and $10 vps — rails + postgres + a sender process; you still want an upstream relay for deliverability. Compare against SendGrid's Free 100/day; Essentials $19.95/mo for 50k; pricing climbs with sender reputation features below.

	Cuttlefishopen-source	SendGridpaid SaaS
Category	Transactional email API	Transactional email API
License / pricing	`AGPL-3.0`	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	mlandauer/cuttlefish ★ 1.62k · last commit 23mo agodead	closed source
Setup time	30min docker-compose (Rails app + Postgres)	SaaS — sign up + bill
Monthly cost	$10 VPS — Rails + Postgres + a sender process; you still want an upstream relay for deliverability.	from $19.95/user/mo (Free 100/day; Essentials $19.95/mo for 50k; pricing climbs with sender reputation features)

Switching from SendGrid to Cuttlefish

Cuttlefish exposes SMTP — point your app at it via standard `MAIL_HOST`/`MAIL_PORT` env. If you were using SendGrid's HTTP API, swap to your language's SMTP library (Nodemailer, smtplib, ActionMailer SMTP). Cuttlefish then handles bounces, click/open tracking, and a per-email log via its dashboard.

Good fit for: Rails / Ruby shops that prefer SMTP + an inspectable web UI over an HTTPS API.
Weak at: Smaller community than Postal; no native HTTPS send API — you go through SMTP.

Other open-source self-host alternatives to SendGrid

Postal
MIT30min docker-compose (Postal + MariaDB + RabbitMQ)$5-10 VPS for the server itself; deliverability matters more than cost — most setups relay through Amazon SES at $0.
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 Cuttlefish a free alternative to SendGrid?

Yes — Cuttlefish is open source under AGPL-3.0. Self-host cost: $10 VPS — Rails + Postgres + a sender process; you still want an upstream relay for deliverability.. 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 Cuttlefish take to set up vs SendGrid?

Self-hosting Cuttlefish: 30min docker-compose (Rails app + Postgres). SendGrid is a hosted SaaS — sign up and you're in.

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

Good fit for: Rails / Ruby shops that prefer SMTP + an inspectable web UI over an HTTPS API.. Weak at: Smaller community than Postal; no native HTTPS send API — you go through SMTP..