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. kill signature verification apk download
View full certificate chains including protocol version, cipher suite, issuer details, validity dates, and SHA-256 fingerprints. Some apps use signature verification to ensure the
24-code error database with actionable troubleshooting hints. Port connectivity testing detects ISP blocking, firewall issues, and DNS failures. Modifying system files like services
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.
Some apps use signature verification to ensure the app was downloaded from the official Play Store. Disabling this allows the app to run even if the license check fails. 🧪 App Testing
It modifies the services.jar file in your system.
Modifying system files like services.jar can lead to boot loops.
Lucky Patcher is the most popular tool for this purpose. It offers a specific "Patch to Android" feature.
Users often want to change the UI, remove ads, or add features to existing apps. Since the user doesn't have the original developer’s private key, they cannot re-sign the modded APK with the original signature. 🔓 Bypassing License Checks
It hooks into the Package Manager Service to bypass the signature check during installation. 3. Manual Smali Editing This is the "hard way" and involves decompressing the APK. Tool: Use APK Easy Tool or MT Manager.
Developers frequently test different versions of an app. Killing verification allows them to overwrite official versions with test builds without uninstalling the app and losing data. Methods to Disable Signature Verification
If the signatures don't match, Android will block the installation with an "App not installed" error. Why Users Seek to Kill Signature Verification
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
Some apps use signature verification to ensure the app was downloaded from the official Play Store. Disabling this allows the app to run even if the license check fails. 🧪 App Testing
It modifies the services.jar file in your system.
Modifying system files like services.jar can lead to boot loops.
Lucky Patcher is the most popular tool for this purpose. It offers a specific "Patch to Android" feature.
Users often want to change the UI, remove ads, or add features to existing apps. Since the user doesn't have the original developer’s private key, they cannot re-sign the modded APK with the original signature. 🔓 Bypassing License Checks
It hooks into the Package Manager Service to bypass the signature check during installation. 3. Manual Smali Editing This is the "hard way" and involves decompressing the APK. Tool: Use APK Easy Tool or MT Manager.
Developers frequently test different versions of an app. Killing verification allows them to overwrite official versions with test builds without uninstalling the app and losing data. Methods to Disable Signature Verification
If the signatures don't match, Android will block the installation with an "App not installed" error. Why Users Seek to Kill Signature Verification
Verify SMTP servers, test API providers, inspect TLS certificates, and diagnose delivery issues. No cost, no limits.