Posthorn
Communication & EmailA unified outbound mail gateway that lets self‑hosted apps forward email through a single provider (Postmark, Resend, Mailgun, AWS SES or SMTP relay).
Features
- Three ingress methods: HTTP form handling, JSON API endpoint, and an SMTP listener.
- Supports five outbound transports: Postmark, Resend, Mailgun, AWS SES, and generic outbound‑SMTP relays.
- Built‑in honeypot, rate limiting, origin/Referer checks, optional CSRF for web forms.
- Single Go binary with TOML configuration—no separate mail server required.
- Works around cloud hosts that block outbound SMTP by acting as a relay.
Recent releases
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Install & Platforms
Install via
docker
Platforms
linux
macos
windows
arm64
Alternative to
Stalwart
Mailcow
iRedMail
Postal
Hyvor Relay
Listmonk