Cost / License
- Free
- Open Source (MIT)
Platforms
- Mac
- Windows
- Linux

VaultSandbox is described as 'A self-hosted SMTP testing gateway designed to replicate production email behavior—including TLS, DNS, authentication, and spam scoring—so your email tests reflect real-world conditions' and is a automated testing tool. There are more than 10 alternatives to VaultSandbox for a variety of platforms, including Web-based, Mac, Windows, Linux and Docker apps. The best VaultSandbox alternative is Mailpit, which is both free and Open Source. Other great apps like VaultSandbox are MailHog, Mailcatch.app, Mailtrap and FakeSMTP.

MailHog is an email testing tool inspired by MailCatcher, but easier to install.

An email sandbox to inspect and debug emails in dev, staging, and QA environments before sending them to recipients in production.

Mailtrap is an Email Delivery Platform for businesses and individuals to Test, Send, and Control their email infrastructure performance.



FakeSMTP is a Free Fake SMTP Server with GUI for testing emails in applications easily. It is written in Java.



Mailisk is an E2E email testing platform. It allows you to receive emails with code and automate email flows. You get a unique subdomain and access to unlimited custom email addresses.

Email Testing for QA & Development Teams. Catch every email your product sends, analyze it's contents, follow links and test deliverability all via the Mailosaur API.

MailDev is a simple way to test your project's generated emails during development with an easy to use web interface that runs on your machine built on top of Node.js.

Sendpit is a hosted email testing sandbox designed for developers and QA teams. It allows applications to send emails to a safe inbox where messages can be inspected, debugged, and tested without being delivered to real users.

DevMail is an email sandbox service for software developers. It allows developers to capture emails from various environments and inspect HTML, text, source code, raw headers, and attachments, and improve deliverability by analyzing email spam scores.
