MailLinter – AI-powered email testing for deliverability, accessibility, and compatibility

Summary: MailLinter is a self-hosted email testing tool that captures emails via a local SMTP server and analyzes them using AI for spam scores, accessibility, and client compatibility. It integrates SpamAssassin and supports over 15 email clients, providing prioritized fixes through GPT-4o and Claude. Setup requires a single Docker command and an OpenAI key.

What it does

MailLinter traps emails locally to prevent accidental sends, inspects headers and content, and uses AI to evaluate spam signals, WCAG accessibility, and compatibility across major email clients.

Who it's for

It is designed for developers needing reliable email testing in local development before production deployment.

Why it matters

It addresses the complexity of email testing in development by providing automated, comprehensive analysis without relying on external SaaS services.