Hyvor Relay
Self-hosted email API alternative to AWS SES & Mailgun. Open-source AGPL-3.0 with enterprise features, automated deliverability, and cloud version coming 2026.
585
AGPL-3.0
Alternative to: Resend
Best Open Source Email Platforms
Explore open-source Email Platforms with repository signals, licensing, categories, and product details for faster software evaluation.
Email Platforms7 tools
Open-source tools
Showing 7 of 7 curated projects from this topic.
DoubleZero
00 is an open-source email API and infrastructure solution that allows developers to own and control their email stack.
1,242
AGPL-3.0
Alternative to: Resend
Postal
Self-hosted email delivery platform with powerful features for transactional and bulk emails, offering full control and customization.
16,516
MIT
Alternative to: Resend
Sendportal
Open-source email marketing platform offering unlimited subscribers, campaigns, and workspaces. Self-hosted solution with powerful API and beautiful interface.
2,130
MIT
Alternative to: Resend
Freescout
Self-hosted email management system with shared inboxes, automation, and powerful collaboration features for efficient customer support.
4,226
AGPL-3.0
Alternative to: FreshDesk
Plunk
Plunk unifies marketing, transactional, and broadcast emails into a single, complete solution for businesses of all sizes.
5,095
AGPL-3.0
Alternative to: Resend
Keila
Self-hosted newsletter platform with powerful features, data protection, and full control over your mailing lists and campaigns.
2,092
AGPL-3.0
Alternative to: Substack