MailLinter is a free email testing tool that helps developers test emails before sending them to real users. It provides spam analysis with SpamAssassin, WCAG accessibility checking, email client compatibility testing, and AI-powered deliverability scoring using GPT-4o and Claude that synthesizes all results into prioritized actionable fixes.

How do I install MailLinter?

MailLinter can be installed with a single Docker command: docker run -p 2525:2525 -p 8547:8547 nunomsde/maillinter. It takes less than 30 seconds to set up and requires no configuration. Point your application to localhost:2525 for SMTP and open localhost:8547 to view results.

Is MailLinter free to use?

Yes, MailLinter is completely free to use and all features are currently included, including AI analysis (you provide your own API key). An annual license is planned that will unlock premium features like team sharing and login protection. Core email testing will always remain free.

What email clients does MailLinter test compatibility for?

MailLinter tests email compatibility across 15+ email clients including Gmail, Outlook (desktop and web), Apple Mail, Yahoo Mail, Samsung Mail, and more. It covers approximately 95.7% of the email client market share.

How does AI email analysis work in MailLinter?

MailLinter integrates with OpenAI GPT-4o and Anthropic Claude to provide intelligent deliverability analysis. The AI ingests all test results—spam scores, accessibility issues, compatibility problems—and synthesizes them into a Deliverability Score with prioritized, actionable recommendations ranked by impact.

Terms of Service - MailLinter

Name: MailLinter
Availability: InStock
Rating: 4.9 (127 reviews)
Author: MailLinter

Acceptance of Terms

By accessing and using MailLinter, you agree to be bound by these Terms of Service. If you do not agree to these terms, please do not use our software.

Description of Service

MailLinter is a free email testing tool that provides:

Local SMTP server for capturing test emails
AI-powered email analysis (requires your own API keys)
Spam score checking via SpamAssassin
Email client compatibility testing
Accessibility compliance checking

Use License

MailLinter is provided as free software. You are granted a license to:

Use the software for personal and commercial purposes
Run the software locally via Docker

This license is subject to the terms of service outlined on this page.

User Responsibilities

When using MailLinter, you agree to:

Use the software only for lawful purposes
Not use the software to send spam or malicious emails
Comply with all applicable laws and regulations
Secure your own API keys and credentials
Not attempt to reverse engineer or compromise the software

Third-Party Services

MailLinter integrates with third-party services including OpenAI and Anthropic. Your use of these services is subject to their respective terms of service and pricing.

Disclaimer of Warranties

MailLinter is provided "as is" without warranty of any kind, express or implied. We do not guarantee that the software will be error-free, uninterrupted, or meet your specific requirements.

Limitation of Liability

In no event shall MailLinter or its contributors be liable for any indirect, incidental, special, consequential, or punitive damages arising out of or related to your use of the software.

Changes to Terms

We reserve the right to modify these terms at any time. Changes will be effective immediately upon posting to this page. Your continued use of MailLinter constitutes acceptance of the modified terms.

Contact Us

If you have any questions about these Terms of Service, please contact us at nuno.msde@gmail.com