6 open-source Transactional Email vendors
Open-source software for Transactional Email that you can self-host, with auditable source code — regardless of the developer's headquarters.
- vendors scored
- 6
- European
- 3
- foreign-owned
- 2
- last checked
- 12 October 2026
Vendors, scored
Score per vendor: 0 = high exposure, 100 = sovereign
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- Sovereignty score 94 out of 100MJMLFrance · Self-hosted / open source · owner in SwedenOpen-source markup language and framework for responsive email HTML, created by Mailjet (Paris), part of Sweden's Sinch AB.
- Sovereignty score 94 out of 100NodemailerEstonia · Self-hosted / open sourceOpen-source email sending library for Node.js (SMTP and more), maintained by an individual developer and the Estonian company Postal Systems OÜ (EmailEngine).
- Sovereignty score 94 out of 100ZoneMTAEstonia · Self-hosted / open source · owner in NetherlandsOpen-source outbound SMTP server (MTA) for Node.js with queues, DKIM, IP pools and delivery zones, built by Zone Media OÜ of Estonia.
- Sovereignty score 79 out of 100NovuIsrael · Self-hosted / open sourceOpen source notification infrastructure from Israeli company Noti-Fire Apps Ltd. (d/b/a Novu) for in-app, email, push and chat notifications; self-hostable or cloud.
- Sovereignty score 77 out of 100OpenSMTPDCanada · Self-hosted / open sourceOpen-source SMTP server from the OpenBSD project, under the ISC licence, for self-hosted outbound mail.
- Sovereignty score 69 out of 100KumoMTAUnited States · Self-hosted / open sourceOpen-source MTA (Apache 2.0) for high-volume outbound email with Lua scripting and traffic shaping, from Kumo Corp (US).
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