SMTP & Email API Test Utility
A free, native tool for testing SMTP relay servers and email API providers. Built for email administrators, developers, and IT professionals who need to quickly verify email delivery configurations.
Windows, macOS & CLI available now
Clean, intuitive interface designed for professionals. Test SMTP servers, preview HTML emails, and diagnose delivery issues.
Main Interface - SMTP Configuration
Send test emails through any SMTP server or choose from 12 integrated API providers. Inspect TLS certificates, diagnose delivery issues, and securely store credentials.
Save SMTP and API credentials securely with AES-256-GCM encryption. Master password protection keeps your credentials safe between sessions. windows 11 pro nexus liteos 23h2 build 2263124
View full certificate chains including protocol version, cipher suite, issuer details, validity dates, and SHA-256 fingerprints. Here are some of the key features that
24-code error database with actionable troubleshooting hints. Port connectivity testing detects ISP blocking, firewall issues, and DNS failures. reduced system footprint
Compose in plain text or HTML with auto-detection. Live preview with rendered and raw source views. 6 preloaded templates included.
One-click sending via SendGrid, Mailgun, Amazon SES, Postmark, Brevo, and 7 more providers with built-in authentication handling.
No analytics, no tracking, no data collection. Your credentials stay local. App Sandbox enabled for maximum security.
One-click API-based sending with all major email service providers. Authentication handled automatically.
Here are some of the key features that make Windows 11 Pro Nexus LiteOS 23H2 Build 22631.24 an attractive option:
In the realm of custom Windows installations, "Lite" builds occupy a specific niche designed for users seeking maximum performance, reduced system footprint, and a bloatware-free experience. stands out as a prominent modification of Microsoft's latest operating system. This build is essentially a heavily tweaked version of the official Windows 11 23H2 release, tailored by the Nexus development team to optimize resource usage and streamline the user interface.
Live HTML Email Preview
6 Pre-loaded Email Templates
No subscriptions, no limitations, no strings attached.
Windows 10/11 (x64)
Version 1.0.7.0
macOS 14.0+ (Universal)
Version 1.08
Python (Cross-platform)
Open Source
Here are some of the key features that make Windows 11 Pro Nexus LiteOS 23H2 Build 22631.24 an attractive option:
In the realm of custom Windows installations, "Lite" builds occupy a specific niche designed for users seeking maximum performance, reduced system footprint, and a bloatware-free experience. stands out as a prominent modification of Microsoft's latest operating system. This build is essentially a heavily tweaked version of the official Windows 11 23H2 release, tailored by the Nexus development team to optimize resource usage and streamline the user interface.
Verify SMTP servers, test API providers, inspect TLS certificates, and diagnose delivery issues. No cost, no limits.