Cuttlefish vs Postal
Self-host pick — both replace SendGrid (Transactional email API).
Both Cuttlefish and Postal self-host as a replacement for SendGrid (Transactional email API). Pick Cuttlefish if you want a AGPL-licensed codebase (AGPL-3.0); pick Postal for MIT (MIT). Both run in roughly the same cost bracket — $10 vps — rails + postgres + a sender process; you still want an upstream relay for deliverability vs $5-10 vps for the server itself; deliverability matters more than cost — most setups relay through amazon ses at $0.
| Cuttlefishopen-source | Postalopen-source | |
|---|---|---|
| License | AGPL-3.0 | MIT |
| Setup time | 30min docker-compose (Rails app + Postgres) | 30min docker-compose (Postal + MariaDB + RabbitMQ) |
| Monthly cost | $10 VPS — Rails + Postgres + a sender process; you still want an upstream relay for deliverability. | $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. |
| GitHub | mlandauer/cuttlefish | postalserver/postal |
| Replaces | SendGrid | SendGrid |
Good fit for
Cuttlefish
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.
Postal
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 SendGrid's self-host options including both —
how the CLI works →
FAQ
Which is easier to self-host, Cuttlefish or Postal?
Cuttlefish: 30min docker-compose (Rails app + Postgres). Postal: 30min docker-compose (Postal + MariaDB + RabbitMQ).
What does each cost to run?
Cuttlefish: $10 VPS — Rails + Postgres + a sender process; you still want an upstream relay for deliverability.. Postal: $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.. Both projects are free and open source.
Do Cuttlefish and Postal replace the same SaaS?
Yes — both are open-source alternatives to SendGrid.