🔒 PDF Encryption & Email Sending Tool

A powerful desktop application that encrypts PDF files using passwords from Excel and automatically sends them via email.

This tool is designed for organizations that need to securely distribute documents in bulk — such as HR departments, accounting teams, educational institutions, and corporate operations.

🚀 What Does This Application Do?

The program allows you to:

  • 📄 Read PDF filename, password, and email address from an Excel file

  • 🔐 Encrypt each PDF with a unique password

  • 📧 Automatically send the encrypted file to the corresponding recipient

  • 📊 Monitor the sending process in real time

Instead of manually encrypting and sending each document one by one, everything is completed in a single automated workflow.

 

🧩 How It Works

 

1️⃣ Prepare the Excel File

Your Excel file must follow this format:

PDF File Name Password Email Address
document1.pdf 12345 [email protected]
document2.pdf abc987 [email protected]

Required structure:

  • Column A: PDF filename (including .pdf extension)

  • Column B: Password

  • Column C: Email address

Each row represents one recipient and one encrypted document.

 

 

2️⃣ Select the PDF Folder

After selecting the folder containing your PDF files, the application:

  • Compares filenames with the Excel file

  • Marks matched files as ✅ Found

  • Marks missing files as ❌ Not Found

This preview step ensures there are no mismatches before encryption begins.

 

 

3️⃣ Choose the Output Folder

Encrypted PDFs are saved in a timestamped subfolder such as:

 
output_20260213_143522

The original files are never modified or overwritten.

 

 

4️⃣ Configure Gmail SMTP Settings

The application sends emails using Gmail SMTP.

You need:

  • Gmail address

  • Sender name

  • 16-character Google App Password

To generate an App Password:

  1. Go to Google Account → Security

  2. Enable 2-Step Verification

  3. Open “App Passwords”

  4. Select Mail + Windows Computer

  5. Copy the generated 16-character password

The credentials are securely stored locally in a configuration file.

 

 

5️⃣ PDF Encryption Process

For each matched file, the application:

  • Reads the PDF

  • Applies password protection

  • Saves a new encrypted version

Example:

 
document1.pdf → document1_encrypted.pdf

Encryption is applied using standard PDF password protection.

 

 

6️⃣ Automatic Email Sending

Once encryption is completed:

  • A sending window opens

  • Each recipient is processed sequentially

  • Status indicators show:

    • ✅ Successfully sent

    • ❌ Failed

The system uses:

  • Port 587 (STARTTLS)

  • Fallback to 465 (SSL) if needed

 

 

✉️ Customizable Email Template

You can fully customize the email subject and body.

Available dynamic variables:

  • {FILENAME} → PDF filename

  • {PASSWORD} → Assigned password

Example:

Dear Recipient,
 
Please find your encrypted PDF document attached. File: {FILENAME} Password: {PASSWORD}
 
Kind regards,
Your Company
 
The system automatically replaces the variables before sending.
 
 

 

 Security

  • PDF encryption using industry-standard password protection

  • Gmail App Password authentication (no plain account password required)

  • Works fully offline except for email sending

  • No cloud storage or external upload

All files are processed locally on your device.

 

 

 Ideal For

  • HR departments sending confidential documents

  • Finance teams distributing secure reports

  • Legal document distribution

  • Bulk secure invoice delivery

  • Any workflow requiring password-protected PDF distribution

 

 

System Requirements

  • Windows OS

  • .NET (if packaged accordingly)

  • Gmail account with App Password enabled

 

 

Support

If you have questions, issues, or feedback about PDF Encryption & Send Mail, please contact us at:

Contact

Email: [email protected]