Requirements

Most people are better off on the hosted version at app.programmableinbox.com — self-host only if you specifically want your mail to stay on infrastructure you control. ProgrammableInbox self-hosts via Docker only; there's no supported from-source install path for running it in production. See Quickstart (Docker) for the actual steps — this page just covers what the machine needs.

Minimum machine requirements

Resource	Minimum	Recommended
CPU	1 vCPU	2 vCPU
Memory	2 GB	4 GB
Disk	10 GB free	20 GB+ free (grows with mail volume and Postgres/Redis data)
OS / architecture	Any Linux, macOS, or Windows host that runs Docker; images are multi-arch (linux/amd64, linux/arm64)	Linux server, for a long-running deployment
Network	Outbound internet (to pull images and reach the Resend API)	Also a public IP + domain name, if you want the instance to receive real mail

These sizes cover the app, Postgres, and Redis running together in the same Compose stack. They're a starting point, not a benchmark — a busy inbox with heavy async webhook processing or a large searchable mail archive will want more of all three.

Software prerequisites

• Docker Engine with the Compose plugin — docker compose version should work. Docker Desktop covers this on macOS/Windows; most Linux distros need the Compose plugin installed alongside Docker Engine.

That's the only local install requirement — there's no Node.js, no Postgres, and no build toolchain to set up yourself.

External services

A Resend account is required — self-hosted or not, this product doesn't send or receive a single email without one. Before you write your .env:

1. Create a Resend account and add + verify the domain you want inboxes to live on — this becomes your EMAIL_INBOX_ALLOWED_DOMAINS value.
2. Create a webhook pointed at https://<your-host>/api/webhooks/email for the email.received event. This route is the only way mail reaches the app, so nothing arrives until it's set up.
3. While you're there, grab both credentials you'll need: your API key (RESEND_API_KEY) and the webhook's signing secret (RESEND_WEBHOOK_SECRET). Both go into .env — see Quickstart (Docker) → Configure .env.

A placeholder value for both lets the app boot and the UI load for a first look, but you won't receive a real message until they're set to the values above.

Next step

Ready to run it? See Quickstart (Docker).