PayFlow – Excel-to-Mail Gateway with Credit System

PayFlow is a specialized email tool designed to bridge the gap between Microsoft Excel and professional communication. 

It allows you to send personalized messages directly from your workbooks while utilizing a built-in credit-based billing system.

How it works: 

Credit Management: Every sent email costs 25 credits.

Starting Balance: New users start with 500 credits (allowing for  20 emails).

Easy Top-up: Once credits are exhausted, they can be recharged via a QR code system. Users receive a unique one-time password (OTP) based on a secure time-stamped formula to unlock new credits.

Core Features:

High Compatibility: Seamlessly integrates with all standard mailto: clients like Outlook or Thunderbird.

Robust Text Processing: Automatic conversion to UTF-8 standard. Emojis, special characters, and umlauts are recognized and displayed correctly.    

Loss Prevention: Built-in protection prevents sending empty emails, ensuring no credits are wasted by accident.

Security First: Password protection with mandatory registration upon first launch. A secure code system prevents the reuse of recharge tokens.    

Fully Customizable: The application is Open Source. You have full control over the source code and can freely set your own pricing for credit distribution.

Easy Integration: Can be conveniently embedded into any existing Excel workbook.

Ideal for:

Communities, clubs, small platforms, or e-commerce shops looking for a lightweight, transparent way to manage their outreach.