Best Open Source Alternatives to Postmark

Compare the best free and open-source alternatives to Postmark — self-hosted and desktop replacements you fully control, ranked by GitHub stars, license and platform support.

Curated by open-source.store · Updated November 2026 · 7 alternatives

Postmark

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Postmark alternatives compared

Open-source alternatives to Postmark, compared by stars, license and platform
Tool		License	Platforms	Self-hosted
Plunk	5,573	AGPL-3.0	Web	No	Nov 2026	Visit
useSend	4,778	AGPL-3.0	DockerLinux	Yes	Oct 2026	Visit
Sendune	2,304	MIT	Web	No	Jun 2026	Visit
DoubleZero	1,246	AGPL-3.0	DockerLinux	Yes	Oct 2024	Visit
Sessy	946	—	DockerLinux	Yes	Oct 2026	Visit
Hyvor Relay	919	AGPL-3.0	DockerLinux	Yes	Nov 2026	Visit
Wraps	66	—		No	Nov 2026	Visit

Top open-source Postmark alternatives

Plunk5,573AGPL-3.0

Plunk is an open-source email platform replacing Resend and Mailchimp with zero contact fees, automated workflows, and self-hosted Amazon SES delivery.

Web

vs Postmark: a free, open-source option you fully control, licensed AGPL-3.0.

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useSend4,778AGPL-3.0

Open-source email delivery platform pairing a Next.js dashboard with Amazon SES to send transactional and marketing messages without per-contact fees.

DockerLinux

vs Postmark: a free, open-source option you fully control, licensed AGPL-3.0.

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Sendune2,304MIT

Open-source drag-and-drop HTML email designer that exports portable, cross-client email templates without vendor lock-in or recurring per-contact fees.

Web

vs Postmark: a free, open-source option you fully control, licensed MIT.

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