Mailpit is a small, fast, low memory, zero-dependency, multi-platform email testing tool & API for developers.

It acts as an SMTP server, provides a modern web interface to view & test captured emails, and includes an API for automated integration testing. Mailpit was originally inspired by MailHog which is no longer maintained and hasn't seen active development or security updates for a few years now.

## Features

- Runs entirely from a single static binary or multi-architecture Docker images.

- Modern web UI with advanced mail search to view emails (formatted HTML, highlighted HTML source, text, headers, raw source, and MIME attachments including image thumbnails), including optional HTTPS & authentication.

- SMTP server with optional STARTTLS or SSL/TLS, authentication (including an "accept any" mode).

- A REST API for integration testing.

- Real-time web UI updates using web sockets for new mail & optional browser notifications when new mail is received.

- Optional POP3 server to download captured message directly into your email client.

- HTML check to test & score mail client compatibility with HTML emails.

- Link check to test message links (HTML & text) & linked images.

- SMTP relaying (message release) - relay messages via a different SMTP server including an optional allowlist of accepted recipients.

- SMTP forwarding - automatically forward messages via a different SMTP server to predefined email addresses.

## Installation

The Mailpit web UI listens by default on http://0.0.0.0:8025 and the SMTP port on 0.0.0.0:1025.