Postal
Open-source, fully-featured mail delivery platform for sending and receiving email.
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Use it free
Open the official tool or demo — no account needed.
Self-host it
Run the open-source version on your own infrastructure.
What is Postal?
Postal is an open-source mail delivery platform designed for websites and web servers to handle both incoming and outgoing email services. It serves as an alternative to commercial email services like Sendgrid, Mailgun, or Postmark, offering full control over email infrastructure while maintaining scalability and security. Developers, system administrators, and organizations requiring custom email solutions use Postal to manage email delivery, logging, and spam filtering without relying on third-party APIs. The tool addresses challenges such as ensuring reliable email delivery, maintaining good IP reputation, and integrating with security tools like SpamAssassin or ClamAV to mitigate spam and malware threats. By allowing deployment on private servers, Postal enables users to tailor email workflows to their specific needs while avoiding vendor lock-in.
How it works
Postal is an open-source email delivery platform that provides full control over outgoing and incoming email services. It enables users to manage email delivery, logging, and security features without relying on external email providers. The tool is designed for developers and system administrators who need customizable email infrastructure. It replaces proprietary email services with a self-hosted solution that supports scalability, security, and integration with existing systems. Postal offers a web interface for managing mail servers, viewing logs, and configuring settings. It supports horizontal scaling, IP pool management for email reputation, and webhooks for real-time delivery notifications. Integration with SpamAssassin, rspamd, and ClamAV allows threat detection for both incoming and outgoing emails.
How to use it
- 1Clone the Postal repository from GitHub and install dependencies. 2. Configure the database (PostgreSQL or SQLite) and SMTP settings in the config file. 3. Set up DNS records for email domains and IP pool configurations. 4. Start the server using Docker or native binaries and access the web interface via a browser. Practical tips: Use Docker for simplified setup, enable TLS for secure communication, and regularly update SpamAssassin rules for improved spam filtering. Monitor logs through the web interface to troubleshoot delivery issues.
What it can do
- self-hosted mail server
Use cases
Assumptions and limitations
Assumptions
- source: https://github.com/postalserver/postal
- license: MIT — free to use
- privacy: Self-hosted — you control your data
Limitations
- Requires significant infrastructure setup and maintenance
- Limited out-of-the-box analytics compared to commercial services
- Community-driven support may lack dedicated enterprise resources
- Complexity in configuring DNS and IP pool management
- Dependence on external tools like SpamAssassin for advanced security
Understanding the result
Open-source, fully-featured mail delivery platform for sending and receiving email.
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
- (postalserver/postal)
- License
- MIT
- Runs locally
- No — requires a network request
- Verification
- Not yet verified
- Input
- Query
- Output
- Text
Built with postalserver/postal. 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 the primary use case for Postal?
Postal is primarily used by developers and system administrators to replace proprietary email services with a self-hosted solution. It enables full control over email delivery, spam filtering, and server management, making it ideal for applications requiring customization, scalability, and security.
How does Postal handle spam and malware detection?
Postal integrates with SpamAssassin, rspamd, and ClamAV to scan incoming and outgoing emails for spam and malware. These tools analyze email headers, content, and attachments to identify threats. Users can configure rules and update virus definitions to enhance detection accuracy.
How do I set up Postal for development testing?
Enable development mode in the config file to hold emails in the queue. Use the web interface to view messages without sending them. Test SMTP configurations locally, and leverage the logging features to debug delivery issues before deploying to production.
How does Postal compare to Sendgrid or Mailgun?
Postal differs from Sendgrid or Mailgun by offering full self-hosted control, whereas these services are cloud-based. Postal provides transparency and customization but requires more infrastructure management. It is better suited for organizations prioritizing data sovereignty over convenience.
What should I do if emails are not being delivered?
Check the web interface logs for delivery errors, verify SMTP and DNS configurations, and ensure IP pools are correctly set up. Test with the development mode enabled to confirm messages are queued properly. Review spam filter logs to identify blocked emails and adjust rules as needed.