Overview:
Hyvor Relay is an open-source, self-hosted email API designed for developers who need to send emails using their own SMTP infrastructure. It provides a simple API for sending emails, along with tools for managing delivery, monitoring performance, and handling bounces and complaints. The project is suitable for organizations, agencies, and developers who require a self-managed email sending platform capable of handling high volumes.
Core Features:
Self-Hosted Email API: Send emails via a straightforward API, using your own SMTP servers.
Multi-Tenancy: Supports multiple tenants with scoped access, suitable for organizations and agencies.
Bounce & Suppression Management: Automatically processes bounced emails and manages suppressions like bounces and unsubscribes.
DNS Automation: Delegates DNS management to a built-in DNS server, reducing manual record configuration.
Webhooks: Provides HTTP callbacks for email delivery events.
Observability & Monitoring: Offers Prometheus metrics, Grafana dashboards, and logs (including SMTP conversations) for monitoring health and performance.
Use Cases:
Developers building or migrating to a self-hosted email sending setup that requires an API-driven approach.
Organizations needing multi-tenant email infrastructure to isolate projects or clients, such as agencies managing email for multiple brands.
Teams requiring detailed email delivery monitoring with access to logs, SMTP conversation records, and integration with monitoring tools like Prometheus and Grafana.
Administrators managing high-volume transactional or distributional email who need to isolate queues and handle greylisting automatically.
Why It Matters:
Hyvor Relay provides a developer-focused, self-hosted email API that gives teams direct control over their email infrastructure. Its multi-tenant architecture, DNS automation, and built-in handling of bounces, greylisting, and feedback loops reduce the operational overhead of managing email delivery at scale. The combination of a PHP/Symfony backend with Go-based workers and a PostgreSQL queue offers a specific technical approach for those looking to self-host a high-throughput email platform.
