What is SimpleRelay?

SimpleRelay is a self-hosted SMTP relay for homelabs and small teams that sends outgoing mail through various upstream providers like Gmail, Outlook, or custom SMTP servers, choosing the right one based on the sender address. Its web interface includes a setup wizard that auto-detects provider settings, checks DNS records (SPF, DKIM, DMARC), and enforces IP whitelists with optional SMTP authentication. You can view searchable mail logs, monitor provider health, and manage users, proxies, and sending limits from an admin panel. The whole stack runs in one Docker Compose file with Postfix, PostgreSQL, FastAPI, and a React frontend. It works on a LAN without a public IP or port forwarding.

Should you self-host SimpleRelay?

SimpleRelay scores 46/100 on selfhost.directory (how scoring works) and ranks #77 of 106 in Email. It has 189 GitHub stars.

It shipped 2 stable releases in the past year. The latest, v1.1.0, came out on 20 June 2026. New versions land roughly every 5 days.

Setup is moderate: expect some configuration beyond a single command. It is MIT-licensed and written mostly in Python.

Its closest alternative on selfhost.directory is Listmonk (80/100, 24 017 stars). It scores higher overall, so compare the two before you pick. See SimpleRelay vs Listmonk side by side.