MailLinter

Email Testing Tool

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Docker Ready • SpamAssassin Integrated • Production Ready

Professional Email Testing
Made Simple

Test HTML emails, validate spam scores with SpamAssassin, check compatibility across 15+ email clients. The complete email testing platform for developers and email marketers.

Quick start in one command:

docker run -p 2525:2525 -p 8547:8547 nunomsde/maillinter:latest

Then open http://localhost:8547 in your browser

See MailLinter in Action

Experience the complete email testing workflow. From sending your first test email to analyzing deliverability across 15+ email clients.

Product Showcase
15+
Email Clients Supported
100%
Docker Compatible
< 2min
Setup Time
0
Configuration Required

Everything You Need for Email Testing

From SMTP capture to spam analysis, from compatibility testing to professional reporting. MailLinter provides a complete email testing ecosystem.

Professional SMTP Testing

Capture emails on port 2525 with advanced MIME parsing and attachment support

SpamAssassin Integration

Industry-standard spam detection with real-time scoring and rule categorization

15+ Email Client Compatibility

Test compatibility across Outlook, Gmail, Apple Mail, Yahoo, Thunderbird and more

Responsive Email Preview

Preview emails on desktop, tablet, and mobile with real-time rendering

CSS/HTML Validation

Advanced parsing with actionable compatibility warnings and suggestions

Link Validation

Automatic validation of email links with response times and status codes

Docker Ready

Multi-architecture Docker support (amd64/arm64) with one-command deployment

API Access

Access the MailLinter API to integrate with your own applications

Built-in testing tools

Built-in testing tools to help you test your email

Why Choose MailLinter?

Built by email experts for email professionals. No complex setup, no recurring costs, just powerful email testing.

Lightning Fast Setup

One Docker command and you're testing emails in seconds

Universal Compatibility

Works on any platform with Docker support

Team Ready WIP

Share results and collaborate on email quality

AI-Powered Insights WIP

AI-powered insights to help you improve your email deliverability and understanding of your email data

Test Against 15+ Email Clients

Ensure your emails look perfect across all major email clients with our comprehensive compatibility testing.

Client Support Matrix

Outlook 2019-365
28.5% market share
partial
Gmail Desktop
27.8% market share
excellent
Apple Mail
19.7% market share
good
Outlook 2013-2016
8.2% market share
limited
Gmail Mobile
7.1% market share
excellent
Yahoo Mail
4.1% market share
good
Thunderbird
2.3% market share
excellent
Others
2.3% market share
varied

Comprehensive Testing

  • CSS property compatibility analysis
  • HTML element support validation
  • Media query responsiveness testing
  • Link validation with response times
  • Image and attachment compatibility

Market Coverage

95.7%

Combined market share coverage across all supported email clients, ensuring your emails reach virtually every recipient.

Real-time

Analysis on email arrival

Weighted

Scores by market share

Actionable

Suggestions for fixes

Industry Standard

SpamAssassin Integration

Built-in SpamAssassin integration provides professional spam analysis with detailed rule breakdowns and actionable insights to improve email deliverability.

Real-time Spam Scoring

Ham (Clean Email)
2.1 / 5.0
Suspicious
4.8 / 5.0
Spam
8.2 / 5.0

Performance Metrics

< 100ms
Analysis time
100%
Rule coverage

Rule Categories

Bayes

BAYES_50, BAYES_95

Bayesian spam probability analysis

Authentication

DKIM_VALID, SPF_PASS

DKIM, SPF, DMARC validation

DNS/RBL

URIBL_BLOCKED, DNS_FROM_RFC_DSN

DNS blacklist checking

Content

HTML_MESSAGE, SUBJECT_NEEDS_ENCODING

Message content analysis

Headers

FROM_MISSING, INVALID_DATE

Email header validation

Network

RCVD_IN_DNSWL, RELAY_IS_GMAIL

Network-based tests

Bundled Installation

SpamAssassin comes pre-configured and ready to use. No separate installation required.

Docker

Automatic installation with consistent environment across all platforms

Secure by Design

SpamAssassin is a secure and reliable email filtering system that is designed to protect your email from spam and malware.

Optimized Config

Pre-tuned configuration for email testing environments

Get Started in Minutes

Choose your preferred installation method. All options include SpamAssassin and are production-ready.

Docker Run (Fastest)

< 30 seconds

Pull and run from Docker Hub - no setup needed

docker run -d --name maillinter \
  -p 2525:2525 -p 8547:8547 \
  nunomsde/maillinter:latest
Then open http://localhost:8547 in your browser

✅ Advantages

  • No building required
  • Multi-architecture support
  • Instant start

What's Next?

1

Configure Your App

Point your application to send emails to localhost:2525

2

Send Test Emails

Use the web interface to send test emails or trigger from your application

3

Analyze Results

View compatibility reports, spam scores, and get actionable insights