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.

Privacy Policy - MailLinter

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

Introduction

MailLinter ("we", "our", or "us") is committed to protecting your privacy. This Privacy Policy explains how we collect, use, and safeguard your information when you use our email testing tool.

Information We Collect

MailLinter is designed with privacy in mind. As a self-hosted Docker application:

All email data is processed locally on your machine
We do not collect, store, or transmit your email content to our servers
Your API keys (OpenAI, Anthropic) are stored locally and never sent to us
No user accounts or registration is required

Third-Party Services

When you configure AI analysis features, your email content may be sent to:

OpenAI - If you configure GPT-4o analysis
Anthropic - If you configure Claude analysis

These services have their own privacy policies and terms of service. We recommend reviewing them before enabling AI features.

Website Analytics

Our marketing website may collect anonymous usage data to improve our services. This does not include any data from the MailLinter application itself.

Data Security

Since MailLinter runs entirely on your local machine, you maintain full control over your data security. We recommend:

Keeping your Docker installation up to date
Using secure environment variables for API keys
Not exposing MailLinter ports to the public internet

Changes to This Policy

We may update this Privacy Policy from time to time. We will notify you of any changes by posting the new Privacy Policy on this page and updating the "Last updated" date.

Contact Us

If you have any questions about this Privacy Policy, please contact us at nuno.msde@gmail.com