Mail‑Tester is a free web tool that lets you test the quality of your emails by analyzing their spam score. It helps identify issues that may prevent your messages from reaching inboxes.

🔍 Get a temporary email address to send your test message

📊 Receive a detailed report with a spam score (0–10)

⚡ Checks SPF, DKIM, DMARC, and DNS records for proper setup

🛡️ Detects blacklists and spam‑triggering content in your email

🖥️ Simple, web‑based interface – no installation required

🤝 Built by email software engineers, widely trusted by marketers and sysadmins

Perfect for: Marketers, developers, and sysadmins who want to ensure their emails avoid spam filters and reach recipients.

Flipper Zero is a portable, open‑source multi‑tool device designed for pentesters, hardware hackers, and geeks. It combines playful design with powerful functionality for exploring and interacting with digital systems.

📡 Supports radio protocols (sub‑GHz, RFID, NFC, Bluetooth, infrared, iButton)

🔒 Test and interact with access control systems, garage doors, and key fobs

🖥️ Debug hardware via GPIO, SPI, I²C, and UART interfaces

⚡ Fully open‑source firmware – customizable and extendable

🎮 Toy‑like design with a Tamagotchi‑style dolphin companion

🌐 Active community developing plugins, scripts, and extensions

🤝 Perfect for learning, experimenting, and pentesting in a portable form factor

Perfect for: Security researchers, hardware hackers, and curious geeks who want a versatile portable toolkit.