At a Glance:
Hyvor Relay is a self-hosted, open-source email API for developers that uses SMTP to send emails through your own infrastructure, featuring multi-tenancy, queue isolation, and automated bounce and suppression management.
Overview:
Hyvor Relay is a self-hosted email API designed for developers who need to send emails via SMTP using their own infrastructure. It provides a simple API for sending transactional and distributional emails while automatically handling bounces, suppressions, greylisting, and retries. The system includes built-in DNS automation, eliminating manual DNS record management. Hyvor Relay supports multi-tenancy with scoped access and multiple isolated projects per tenant, making it suitable for organizations and agencies managing separate email environments. It also offers observability through Prometheus metrics and Grafana dashboards, along with send logs and SMTP conversation tracking retained for up to 30 days.
Key Decision Points:
Self-hosted deployment: Deploy via Docker Compose or Docker Swarm, requiring users to bring their own infrastructure and SMTP servers.
Scoped multi-tenancy: Supports multiple tenants with isolated access, which is useful for organizations or agencies managing different clients or projects.
Queue isolation: Uses two separate queues for transactional and distributional email to maintain IP reputation separation.
DNS automation included: An in-built DNS server eliminates the need for manual DNS record configuration when routing email traffic.
Observability built in: Exposes Prometheus metrics and includes Grafana dashboards for monitoring performance and deliverability.
Core Features:
Email API: A simple API for sending emails programmatically.
Health checks: Multiple health checks designed to maintain performance and deliverability.
Logs and SMTP conversations: Send logs and full SMTP conversation records available for up to 30 days.
Bounce and suppression handling: Automatically processes bounced emails and manages suppressions including unsubscribes and spam complaints.
DNS automation: A built-in DNS server handles DNS delegation, removing the need to manage DNS records manually.
Webhooks: HTTP callbacks for email-related events.
Use Cases:
Developers who want to run their own email-sending infrastructure rather than relying on third-party email services.
Organizations managing multiple clients or departments that need isolated email environments through multi-tenancy and scoped projects.
Teams that need to separate transactional and marketing email queues to protect IP reputation.
Open-Source Alternative Value:
Hyvor Relay provides a self-hosted email API that can be deployed directly on your own infrastructure using Docker Compose or Docker Swarm. As an open-source project, it allows developers to run and observe email delivery without depending on external SaaS email platforms. The system's built-in DNS automation and Prometheus-based observability reduce operational overhead that often accompanies self-hosted email infrastructure. Its multi-tenancy design further supports isolated management across different projects or clients.
