Mailpit
Multi-platform email testing tool that provides a web UI to view captured emails.
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Self-host it
Run the open-source version on your own infrastructure.
What is Mailpit?
Mailpit is an open-source email and SMTP testing tool designed for developers to simulate and inspect email interactions without sending real messages. It acts as an SMTP server that captures outgoing emails, providing a web-based interface to review messages and an API for automated testing. Developers use Mailpit to debug email functionality, validate templates, and ensure integrations with email services work as intended. The tool addresses the challenge of testing email workflows without risking spam or exposing sensitive data. Its lightweight design, zero dependencies, and multi-platform support make it accessible for teams and individuals working across different operating systems. By replacing deprecated tools like MailHog, Mailpit offers a modern, actively maintained solution for email testing in development and CI/CD pipelines.
How it works
Mailpit is a lightweight SMTP server that intercepts email traffic to allow developers to inspect and test email functionality without sending actual messages. It is built as a single binary or Docker container, making it easy to integrate into development workflows. The primary purpose of Mailpit is to provide a secure, efficient way to debug email-related code, such as form submissions, password resets, or transactional emails, by capturing and displaying emails in a web interface. Mailpit captures emails sent to its SMTP server, displaying them in a modern web interface with filters and search options. It supports SMTP protocols, allows API access for programmatic testing, and includes features like email preview and attachment inspection. As a replacement for MailHog, it adds active development and security updates.
How to use it
- 1Install Mailpit via Docker by pulling the official image and running a container. 2. Configure SMTP settings in the container’s environment variables to direct email traffic to Mailpit. 3. Access the web interface through the container’s exposed port to view captured emails. 4. Use the API endpoints to programmatically retrieve or filter emails during integration tests. Practical tips include using environment variables for customizing behavior, such as setting the domain or enabling TLS, and leveraging Docker Compose for streamlined setup in development environments.
What it can do
- email test interface
Use cases
Assumptions and limitations
Assumptions
- source: https://github.com/axllent/mailpit
- license: MIT — free to use
- privacy: Self-hosted — you control your data
Limitations
- Not suitable for production environments due to lack of email delivery capabilities
- Limited advanced filtering options compared to commercial email testing tools
- Requires manual setup for complex SMTP configurations
- No built-in analytics or reporting for email engagement metrics
- Limited support for non-standard SMTP extensions
Understanding the result
Multi-platform email testing tool that provides a web UI to view captured emails.
Tool details
- Clearly flagged when a network request is needed.
- No account, no sign-up, and no tracking of your content.
- Powered by (MIT).
- Built with
- (axllent/mailpit)
- License
- MIT
- Runs locally
- No — requires a network request
- Verification
- Not yet verified
- Input
- Query
- Output
- Text
Built with axllent/mailpit. OpenToolVault provides the discovery and browser interface while crediting the original project maintainers.
- Built with
- License
- MIT
Open-source project
OpenToolVault is an independent directory. We are not affiliated with or endorsed by this project.
References
- / — GitHub Repository
Upstream project · GitHub
- MIT License
Upstream project
Frequently asked
What is Mailpit and how does it differ from MailHog?
Mailpit is an open-source SMTP testing tool that replaces MailHog, which is no longer actively maintained. Unlike MailHog, Mailpit provides a modern web interface, API for automation, and regular updates. It retains similar core functionality for capturing emails but adds improved performance and security features.
How does Mailpit handle email delivery and storage?
Mailpit acts as an SMTP server that intercepts emails but does not deliver them to external services. Captured emails are stored temporarily in memory or disk (depending on configuration) and can be viewed via the web interface. Emails are not persisted beyond the session unless explicitly exported or backed up.
How can I test email sending with Mailpit in a Node.js application?
Configure your Node.js app to use Mailpit’s SMTP server (e.g., `smtp://localhost:1025`). Send an email via a library like Nodemailer, then access Mailpit’s web interface at `http://localhost:8080` to view the captured message. Use the API endpoint `/api/v1/messages` to programmatically retrieve emails during tests.
How does Mailpit compare to alternatives like Mailtrap or MailHog?
Mailpit is a direct replacement for MailHog, offering similar core features with active development and better performance. Unlike Mailtrap (a commercial service), Mailpit is free and self-hosted. It lacks advanced features like email analytics found in paid tools but provides greater control for developers.
What should I do if Mailpit isn’t receiving emails?
Verify that your application is configured to use Mailpit’s SMTP port (default 1025). Check Docker container logs for connection errors. Ensure no firewalls or security groups block local traffic. Test with a simple script to confirm SMTP relay is functioning, then validate settings in the Mailpit web interface.