Hyvor Relay
Hyvor Relay is an email API for developers that can be used through its hosted service or self-hosted.
What Hyvor Relay is
Hyvor Relay is an email API for developers that can be used through its hosted service or self-hosted. Its REST API sends HTML and plain-text messages, with attachments, custom headers, and multiple recipients. API tools can automate domain setup, suppressions, API keys, and webhooks; event webhooks report deliveries, bounces, and domain verifications. Projects group domains, keys, and webhooks, and each project handles either transactional or distributional email. Relay manages bounces, complaints, and suppressions, with searchable delivery logs retained for 30 days. Self-hosting requires PostgreSQL and uses Docker Compose or Docker Swarm; the product is licensed under AGPL-3.0. It requires OpenID Connect authentication and has no built-in login or signup system. The free plan is available. Cloud Standard is listed at €30/month with 300,000 emails per month included, though its pricing is estimated and will be finalized at launch. Hyvor Relay also supports inbound email, SMTP relay, and dedicated IPs.
Good
- REST API supports attachments and custom headers
- Automates domain setup and webhook management
- Searchable delivery logs retained for 30 days
- Self-hosting includes monitoring integrations
Watch out
- Requires OpenID Connect authentication
- Self-hosting requires PostgreSQL
- Projects handle one email type each
- No built-in newsletter management
Who it suits
It suits developers who need an email API and want a hosted or self-hosted deployment. Teams needing newsletter management should note that it has no built-in newsletter features.
Verdict
Hyvor Relay combines email sending, event reporting, and delivery handling for developer workflows. Choose between its cloud option and AGPL-3.0 self-hosting, while accounting for its OIDC requirement and project-level email-type split.
Plans and prices
From Hyvor Relay's own pricing page, checked 3 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Enterprise License | €10,000 a year | No AGPL-3.0 obligations · volume-based pricing · enterprise support · SLA options · Starting at €10,000/year; tailored pricing |
| Cloud Standard | €30 a month | 300,000 emails/month included · €1 per additional 10,000 emails · priority support · managed deliverability · SLA and uptime guarantee · €30/month*; pricing estimated and will be finalized at launch |
| Self-Hosted Open-Source | Free | Unlimited usage · all features included · AGPL-3.0 obligations · community support · Free forever |
The facts
Each one read from Hyvor Relay's own pages, with the date it was checked.
What it does
- Authentication
- Relay requires OpenID Connect (OIDC) for authentication and does not include its own login or signup system.checked 3 Oct 2026
- Automation
- The scope-based REST API can automate domain setup, suppressions, API keys, and webhooks.checked 3 Oct 2026
- Delivery handling
- Relay manages bounces, complaints, and suppressions, and provides searchable delivery logs with 30 days of retention.checked 3 Oct 2026
- Deployment
- Self-hosting requires PostgreSQL and uses Docker Compose or Docker Swarm; the guide describes single-server and multi-server deployments.checked 3 Oct 2026
- Email sending
- Its idempotent REST API supports HTML and plain text, attachments, custom headers, and multiple recipients.checked 3 Oct 2026
- Email types
- The getting-started guide says each project sends either transactional or distributional email, using separate IP pools to maintain reputation separately.checked 3 Oct 2026
- Integrations
- The self-hosting guide lists built-in Prometheus, Grafana, and Alertmanager integrations for monitoring and observability.checked 3 Oct 2026
- License
- The self-hosted product is licensed under AGPL-3.0, and enterprise licensing changes the terms and support options while retaining the same features.checked 3 Oct 2026
- Monthly send limit
- 300000checked 23 Sep 2026
- Newsletter limitation
- Relay does not include built-in newsletter management features.checked 3 Oct 2026
- Product
- Hyvor Relay is an open-source, self-hostable email API designed for developers.checked 3 Oct 2026
- Projects
- Projects organize domains, API keys, and webhooks, and a project can send either transactional or distributional email, not both.checked 3 Oct 2026
- Security
- The hosting documentation says its HTTP server has built-in application-layer rate limiting and recommends cloud-provider DDoS protection for network-layer attacks.checked 3 Oct 2026
- Webhooks
- Real-time event webhooks report deliveries, bounces, domain verifications, and other events.checked 3 Oct 2026
Money
- Free plan
- Yeschecked 23 Sep 2026
The company
- Headquarters
- Paris, Francechecked 19 Oct 2026
- Maker and location
- HYVOR says it was founded in 2020 and lists its address as Paris, France.checked 3 Oct 2026
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