The best open source alternative to Hyvor Relay is Postal. If that doesn't suit you, we've compiled a ranked list of other open source Hyvor Relay alternatives to help you find a suitable replacement. Other interesting open source alternatives to Hyvor Relay are: Plunk and DoubleZero.
Hyvor Relay alternatives are mainly Email Platforms but may also be Email Marketing & Newsletter Tools or Customer Communication Platforms. Browse these if you want a narrower list of alternatives or looking for a specific functionality of Hyvor Relay.
Self-hosted email delivery platform with powerful features for transactional and bulk emails, offering full control and customization.

Postal is a powerful, open-source mail delivery platform designed for developers and businesses who need reliable, scalable email infrastructure. With Postal, you can take full control of your email sending capabilities, whether for transactional messages or large-scale marketing campaigns.
Key benefits of Postal include:
By choosing Postal, you gain a robust, cost-effective email delivery solution that puts you in the driver's seat, ensuring optimal deliverability and performance for your critical communications.
Looking for open source alternatives to other popular services? Check out other posts in the alternatives series and openalternative.co, a directory of open source software with filters for tags and alternatives for easy browsing and discovery.
Plunk unifies marketing, transactional, and broadcast emails into a single, complete solution for businesses of all sizes.

Plunk is revolutionizing the email marketing and communication landscape with its comprehensive, open-source platform. Here's what makes Plunk stand out:
All-in-One Solution: Plunk combines marketing, transactional, and broadcast emails in one platform, eliminating the need for multiple tools and simplifying your email strategy.
Affordable Pricing: With a cost-effective model of $0.001 per email, Plunk is up to 5 times cheaper than competitors like Mailchimp, Twilio SendGrid, and Mailgun. You only pay for what you use, not for unused contacts.
Privacy-Focused: All data is hosted, stored, and processed in the EU, adhering to strict privacy standards. Plunk prioritizes security, transparency, and data ownership.
Powerful Features:
Responsive Email Editor: Build responsive emails using Plunk's editor or import your own HTML, ensuring your emails look great even in Outlook.
Open-Source Advantage: As an open-source platform, Plunk offers transparency, customizability, and community-driven improvements.
User-Friendly: With an intuitive UI and easy setup, Plunk is accessible for businesses of all sizes and technical expertise levels.
Generous Free Tier: Send up to 3,000 emails per month for free, with no credit card required.
Plunk is trusted by over 1,000 companies, offering a blend of affordability, functionality, and privacy that makes it an attractive alternative to traditional email service providers. Whether you're sending transactional emails, marketing campaigns, or automated sequences, Plunk provides the tools and flexibility to make your email communication delightful and effective.
00 is an open-source email API and infrastructure solution that allows developers to own and control their email stack.

00 empowers developers to take control of their email infrastructure. This open-source solution provides an easy-to-use email API and deployment tools to set up your own email sending capabilities.
Key benefits include:
00 handles the complex parts of email infrastructure setup, allowing developers to focus on building their applications. The roadmap includes features like contact management, broadcasts, and automations to create a comprehensive email platform.
Whether you're looking for a transactional email solution or aiming to build a full-featured email marketing system, 00 provides the foundation for developers to own their email stack while maintaining simplicity and control.