Mailinator
Disposable email testing inboxes with public and private domains
Open-Source Projects
Discover top open-source software, updated regularly with real-world adoption signals.
Discover top open-source software, updated regularly with real-world adoption signals.
Fast, zero-dependency email testing tool for developers
Mailpit is a lightweight SMTP server with a modern web UI and REST API for capturing, viewing, and testing emails during development and automated integration testing.
Mailpit is a high-performance email testing tool designed for developers who need to capture and inspect emails without sending them to real recipients. Built as a single static binary with zero dependencies, it runs on Windows, Linux, and Mac with minimal resource overhead.
The tool provides an SMTP server (default port 1025) that captures all outbound mail, paired with a modern web interface (port 8025) for inspecting messages. View formatted HTML, highlighted source code, headers, MIME attachments with image thumbnails, and raw message data. Real-time web socket updates notify you instantly when new mail arrives.
Mailpit goes beyond basic capture with HTML compatibility scoring, link validation, SpamAssassin integration for spam testing, and screenshot generation. The REST API enables automated integration testing, while optional POP3 support lets you download messages directly into email clients. Message tagging, SMTP relaying, and configurable chaos testing help validate application resilience. With the ability to ingest 100-200 emails per second and handle tens of thousands of messages, Mailpit scales from solo developers to CI/CD pipelines.
When teams consider Mailpit, these hosted platforms usually appear on the same shortlist.
Looking for a hosted option? These are the services engineering teams benchmark against before choosing open source.
Local Development Email Capture
Developers test registration flows, password resets, and notifications without sending real emails or configuring external services
Automated Integration Testing
CI/CD pipelines verify email content, headers, and attachments via REST API assertions in test suites
Email Template Quality Assurance
Marketing teams validate HTML rendering across clients, check link integrity, and score spam likelihood before campaigns
Microservices Email Validation
Docker-based development environments capture emails from multiple services in a single interface for debugging
Mailpit is actively maintained with modern features like HTML compatibility testing, spam checking, link validation, and significantly better performance. It was inspired by MailHog but built from scratch with enhanced capabilities.
Yes, Mailpit supports SMTP relaying to forward captured messages to external servers, with optional recipient allowlists for controlled testing of real delivery.
No, Mailpit automatically prunes emails, keeping the 500 most recent by default. This limit is configurable but the tool is designed for testing, not archival.
The SMTP server supports STARTTLS, SSL/TLS, and authentication including an 'accept any' mode. The web UI supports optional HTTPS and authentication for secure access.
Configure your application to send email via SMTP to localhost:1025. For PHP and other sendmail-based apps, Mailpit can act as a sendmail replacement. Use the REST API for automated testing.
Project at a glance
ActiveLast synced 4 days ago
