Mailtrain is a powerful, self-hosted newsletter application built on top of Nodemailer, designed to provide organizations with a robust and private alternative to commercial email marketing platforms.

The main features of this tool include:

• Large-Scale List Management: It can easily manage lists with millions of subscribers, allowing for manual entries, API integrations, or bulk imports via CSV files.

• Advanced Template Editors: Mailtrain comes integrated with GrapeJS and Mosaico, two sophisticated visual editors, while also offering a code editor for developers who prefer to handcraft their HTML.

• Flexible Sending Options: It allows you to send through any provider supporting the SMTP protocol. It also includes built-in support for handling bounces and complaints via webhooks for major services like SES, SendGrid, and Mailgun.

• Smart Segmentation & Custom Fields: You can create custom fields (text, dropdowns, checkboxes) and use segmentation rules to target specific groups of subscribers within a single list, eliminating the need for multiple redundant lists.

• RSS-to-Email Automation: The platform can automatically track RSS feeds and generate new campaigns as soon as new content is detected, sending them directly to your subscribers.

• Privacy & Security (GPG): Uniquely, it supports GPG encryption, allowing subscribers to receive fully encrypted messages if they provide their public key.

• Analytics & Automation: Includes detailed click statistics for every link in a campaign and supports automation triggers to send specific messages when users perform certain actions.