Mailpit is a multi-platform email testing tool & API for developers.
It acts as both an SMTP server, and provides a web interface to view all captured emails.
Mailpit is inspired by MailHog, but much, much faster.
Features
Runs entirely from a single binary, no installation required
SMTP server (default 0.0.0.0:1025)
Web UI to view emails (formatted HTML, highlighted HTML source, text, headers, raw source and MIME attachments including image thumbnails)
Mobile and tablet HTML preview toggle in desktop mode
Advanced mail search (see wiki)
Message tagging (see wiki)
Real-time web UI updates using web sockets for new mail
Optional browser notifications for new mail (HTTPS and localhost only)
Configurable automatic email pruning (default keeps the most recent 500 emails)
Email storage either in a temporary or persistent database (see wiki)
Fast SMTP processing & storing - approximately 70-100 emails per second depending on CPU, network speed & email size, easily handling tens of thousands of emails
SMTP relaying / message release - relay messages via a different SMTP server including an optional allowlist of accepted recipients (see wiki)
Optional SMTP with STARTTLS & SMTP authentication, including an "accept anything" mode (see wiki)
Optional HTTPS for web UI (see wiki)
Optional basic authentication for web UI (see wiki)
A simple REST API (see docs)
Multi-architecture Docker images