LunaticSMTP Guide

LunaticSMTP Guide

What’s LunaticSMTP?

LunaticSMTP is a handy tool designed for testing email sending applications. It functions as a dummy SMTP server with a user-friendly desktop GUI. Essentially, it intercepts emails sent to it, allowing users to easily view and inspect them. Written in JavaFX, LunaticSMTP requires Java 8+ to operate and is licensed under GPLv3+.

How to set up LunaticSMTP?

Ubuntu (18.04+) and Debian (10+)

Download deb package from latest release page and install it:

apt install ./lunaticsmtp_X.Y.Z-1_all.deb


Usage: lunaticsmtp [options]
    -c, --cleanup      Remove saved on disk emails after shutdown (default:
    -d, --directory    Directory to save incoming messages (default: incoming)
    -h, --help         Show short summary of options
    -j, --jump-to-last Automatically select last received email in GUI
                       (default: false)
    -n, --no-gui       Starts application without GUI (should be used with -s
                       argument) (default: false)
    -p, --port         Specify port for SMTP server (default: 2525)
    -s, --start        Starts SMTP server at application launch (default:
    -t, --tray-mode    Set tray mode (none: disable tray; enable: enable tray;
                       minimize: enable tray and start application minimized)
                       (default: none) (values: [none, enable, minimize])
    -v, --version      Print version information and exit (default: false)
    -w, --write        Save incoming emails to disk (default: false)

LunaticSMTP Alternatives

If you're exploring alternatives to LunaticSMTP, consider Mailcatch, our own project tailored for efficient email testing. Here's what sets Mailcatch apart:

Quick Integration: Get your testing environment up and running in just 5 minutes. Our system seamlessly integrates with your applications, ensuring a smooth setup process.

Organized Testing: Keep your testing environment structured by creating distinct inboxes for different scenarios or review servers. Group them under relevant projects for easy management.

Comprehensive Email Analysis: Dive deep into your emails with Mailcatch. View content, validate headers across various email clients, and more, for thorough testing.

Broad Testing Capability: Easily send test emails directly from your CRM or other email sending services. Simulate multi-recipient sending for comprehensive testing.

Collaboration: Grant access to team members or clients and forward select test emails to approved recipients, fostering collaboration and feedback.

Proactive Support: Count on our expert team of engineers and email deliverability specialists to provide assistance whenever you need it.

Modern Dashboard: Enjoy testing emails with a contemporary, intuitive dashboard design that enhances user experience.

Simple Integration: Integrate Mailcatch effortlessly into your project by copying the email configuration directly into the appropriate file.

Fake SMTP Feature: Preview your emails in the inbox to avoid accidentally sending test emails to real users.

Quick Start:

  • Choose from over 20 code samples or copy the SMTP details.
  • Integrate the configuration into your project.
  • Trigger your email sending function.
  • Instantly view your message in the inbox.
  • With Mailcatch, streamline your email testing process and ensure flawless email delivery in your applications.