Open Source Alternatives to Postmark

An email delivery service that provides SMTP and API infrastructure for sending transactional and promotional emails. The platform allows developers to integrate email capabilities into their software stacks using official libraries for various programming languages including Python, Ruby, Node.js, PHP, and .NET. It features separate message streams to ensure transactional and broadcast emails remain isolated to maintain high deliverability. The service is designed for companies of all sizes, from solo developers to large enterprises, and is deployed as a cloud based API service. Users can manage their email sending through a dedicated app and access detailed documentation for integration. The platform includes features such as DMARC monitoring and optional dedicated IP addresses for high volume senders. It is used to send password reset emails, notifications, and newsletters.

Whether you want to cut software costs or escape vendor lock-in, these open source alternatives to Postmark give you an option you fully own. You can self-host them, so your data stays on infrastructure you control. This page lists 3 open source alternatives to Postmark. The most popular are Postal, useSend and Sessy. Most use the AGPL-3.0 or Custom license, and 3 offer an official Docker image.