📬 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.

🚀 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

📦 Requirements

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

⚙️ Installation

git clone https://git.robott.sk/robott/mail-status.git
cd mail-status
chmod +x mail-status.sh

▶️ Usage

sudo ./script.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`	Filter by date (e.g. `"Mar 27"`)

📌 Examples

Show last 10 records

sudo ./script.sh

Show last 50 records

sudo ./script.sh -l 50

Filter by sender

sudo ./script.sh -f gmail.com

Filter by recipient

sudo ./script.sh -t example.com

Filter by Queue ID

sudo ./script.sh -i 3F2A12345

Filter by date

sudo ./script.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