Hyvor Relay

Hyvor Relay is an email API you run on your own servers. It sends over SMTP from your infrastructure and your addresses, which puts deliverability and IP reputation in your hands rather than a vendor's, while still giving developers the simple send endpoint they expect.

The stack splits by job. PHP with Symfony runs the API backend, Go handles email workers, webhook delivery, the DNS server, and the incoming SMTP server as a single binary, SvelteKit and the Hyvor Design System build the frontend, and PostgreSQL serves as both database and queue. Deployment is Docker Compose or Swarm.

Running your own mail path means handling the parts a provider normally hides.

• Deliverability handling: greylisting, retries, bounces, feedback loops, and suppressions are managed automatically.
• Queue separation: transactional and distributional mail sit in separate queues to protect IP reputation.
• DNS automation: delegate DNS to the built-in server instead of maintaining records by hand.
• Multi-tenancy: tenants get scoped access and each holds isolated projects, which fits agencies and larger organizations.
• Observability: send logs and full SMTP conversations are kept for 30 days, alongside Prometheus metrics and Grafana dashboards.
• Webhooks: HTTP callbacks report email events to your own systems.

Health checks watch performance and deliverability, and scaling means adding more servers and IP addresses as volume grows. The license is AGPL 3.0, with enterprise licensing offered to organizations that need commercial terms or cannot comply with it.