SMTP Penetration Testing

This is a pentesting template for running security assessments against SMTP servers. It covers the standard attack surface: banner grabbing, user enumeration, open relay testing, brute force authentication, and misconfigurations. You get Claude prompts that walk through using nmap scripts, netcat for manual SMTP commands, and hydra for credential attacks. Two security audit tools flag it, which makes sense since it's literally pentesting code. Use this when you're doing authorized security testing on mail servers and want Claude to guide you through the methodology. It's practical if you know what you're doing, but don't run this against infrastructure you don't own.

GitHub stars: 30.2K
last updated: Aug 21, 2026

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Install

$ npx -y skills add davila7/claude-code-templates --skill 'SMTP Penetration Testing' --agent claude-code

Installs into .claude/skills of the current project.

Files

SMTP Penetration Testing

Purpose

Conduct comprehensive security assessments of SMTP (Simple Mail Transfer Protocol) servers to identify vulnerabilities including open relays, user enumeration, weak authentication, and misconfiguration. This skill covers banner grabbing, user enumeration techniques, relay testing, brute force attacks, and security hardening recommendations.

Prerequisites

Required Tools

# Nmap with SMTP scripts
sudo apt-get install nmap

# Netcat
sudo apt-get install netcat

# Hydra for brute force
sudo apt-get install hydra

# SMTP user enumeration tool
sudo apt-get install smtp-user-enum

# Metasploit Framework
msfconsole