# VaultSandbox

> Test email like it behaves in production.

VaultSandbox is a self-hosted, receive-only SMTP testing gateway that behaves like a real SMTP server - including TLS, DNS, authentication, spam filtering/scoring, and failure modes - so your tests stop lying to you.

## Key Features

- **Production Fidelity**: Real SMTP behavior, real TLS, real authentication (SPF, DKIM, DMARC), spam scoring
- **Chaos Engineering**: Inject latency, simulate greylisting, drop connections, return SMTP errors, blackhole messages
- **CI/CD Ready**: SSE-based SDKs for deterministic waits - no polling, no sleeps, no flaky tests
- **Secure by Default**: Receive-only gateway, rate limiting, hardened defaults, optional zero-knowledge encryption
- **Three Deployment Modes**: Localhost (zero-config), Auto Domain (vsx.email), Custom Domain

## Quick Start

Deploy locally with Docker:

```yaml
services:
  vaultsandbox:
    image: vaultsandbox/gateway:latest
    ports:
      - '127.0.0.1:2525:25'
      - '127.0.0.1:8080:80'
    volumes:
      - vsb_data:/app/data

volumes:
  vsb_data:
```

## Documentation

- [Getting Started](https://vaultsandbox.dev/getting-started/quickstart/)
- [Custom Domain Setup](https://vaultsandbox.dev/getting-started/quickstart-custom-domain/)
- [Local Development](https://vaultsandbox.dev/deployment/local-development/)

## Official SDKs

- [Node.js SDK](https://vaultsandbox.dev/client-node) - [npm](https://www.npmjs.com/package/@vaultsandbox/client) - [GitHub](https://github.com/vaultsandbox/client-node)
- [Python SDK](https://vaultsandbox.dev/client-python) - [PyPI](https://pypi.org/project/vaultsandbox/) - [GitHub](https://github.com/vaultsandbox/client-python)
- [Go SDK](https://vaultsandbox.dev/client-go) - [pkg.go.dev](https://pkg.go.dev/github.com/vaultsandbox/client-go) - [GitHub](https://github.com/vaultsandbox/client-go)
- [Java SDK](https://vaultsandbox.dev/client-java) - [Maven Central](https://central.sonatype.com/artifact/com.vaultsandbox/client) - [GitHub](https://github.com/vaultsandbox/client-java)
- [.NET SDK](https://vaultsandbox.dev/client-dotnet) - [NuGet](https://www.nuget.org/packages/VaultSandbox.Client) - [GitHub](https://github.com/vaultsandbox/client-dotnet)

## CLI Tool

- [vsb-cli on GitHub](https://github.com/vaultsandbox/vsb-cli)

## Links

- Website: https://vaultsandbox.com
- Documentation: https://vaultsandbox.dev
- GitHub: https://github.com/vaultsandbox
- Contact: contact@vaultsandbox.com

## Optional

- [Full documentation for LLMs](/llms-full.txt)