📬 Postfix Mail Summary Script

A hardened, production-ready Bash script for analyzing Postfix mail logs with a clean, readable output format.

Designed with security, performance, and portability in mind.

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🚀 Features

• 📊 Clean, formatted output (with optional colors)
• 🔍 Filter by:
  • Sender (--from)
  • Recipient (--to)
  • Queue ID (--id)
  • Date (--date)
• ⚡ Optimized log reading (avoids full log parsing when possible)
• 🛡️ Hardened against:
  • Command injection
  • Regex/ReDoS attacks
  • Memory leaks
  • Log-based DoS
• 🧠 Smart parsing of Postfix logs (including NOQUEUE rejects)
• 🎯 Portable across Linux distributions

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📦 Requirements

• Bash (>= 4.x recommended)
• Standard Linux utilities:
  • awk
  • grep
  • sed
  • tail
  • find
  • zcat

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⚙️ Installation

git clone https://git.robott.sk/robott/mail-status.git
cd mail-status
chmod +x mail-status.sh
▶️ Usage
sudo ./mail-status.sh [OPTIONS]
📖 Options
Option	Description
-h, --help	Show help message
-l, --list NUMBER	Show last X records (default: 10, max: 1000)
-f, --from	Filter by sender (substring match)
-t, --to	Filter by recipient (substring match)
-i, --id	Filter by Queue ID
-d, --date "MMM DD"	Filter by date (e.g. "Mar 27")

Search across all logs for a specific user:

sudo ./mail-status.sh -f user@example.com -d ""

Or search for a specific date:

sudo ./mail-status.sh -f user@example.com -d "Mar 23"
📌 Examples

Show last 10 records

sudo ./mail-status.sh

Show last 50 records

sudo ./mail-status.sh -l 50

Filter by sender

sudo ./mail-status.sh -f gmail.com

Filter by recipient

sudo ./mail-status.sh -t example.com

Filter by Queue ID

sudo ./mail-status.sh -i 3F2A12345

Filter by date

sudo ./mail-status.sh -d "Mar 27"
🖥️ Output Example
DATE-TIME        ID           CLIENT_IP       SENDER                             RECIPIENT                        STATUS       REASON
Mar-27-12:00:01  3F2A12345    192.168.1.10    user@gmail.com                     admin@example.com               sent         [OK]
Mar-27-12:01:05  NOQUEUE      45.12.34.56     spam@bad.com                       user@example.com                REJECT       [Policy]
🔐 Security Design

This script is designed with security-first principles:

✅ Protected Against:

Command injection
AWK injection
Regex-based DoS (ReDoS)
Malicious filenames
Memory exhaustion
Log flooding

🔒 Key Techniques:

Input length limiting
Substring matching (index() instead of regex)
Safe file handling (find -print0, arrays)
Temporary file isolation (mktemp)
Automatic cleanup (trap)
No use of eval
⚡ Performance Optimizations
Reads only last 50,000 lines by default
Full log scan only when necessary (--date, --id)
Avoids unnecessary process spawning
Efficient AWK parsing with memory cleanup
🎨 Color Output
Automatically enabled when running in a terminal
Disabled when piping output (e.g., | less, | grep)
⚠️ Notes
Must be run as root (required for log access)
Works with standard Postfix logs:
/var/log/maillog
Rotated logs (maillog.*, .gz)
🛠️ Future Improvements (Optional)
Real-time monitoring (tail -f)
JSON export for SIEM tools (ELK, Splunk)
Fail2ban integration (auto-block IPs)
Spam pattern detection
📄 License

MIT License

👨‍💻 Author

robott GitHub: https://github.com/robott

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