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SMTP Penetration Testing · dokhacgiakhoa | DecimalAI

securityby dokhacgiakhoa

SMTP Penetration Testing

dokhacgiakhoa/SMTP Penetration Testing

Source dokhacgiakhoa/agent-skills-4-vibe-coding-cli ↗License NOASSERTION

This skill should be used when the user asks to "perform SMTP penetration testing", "enumerate email users", "test for open mail relays", "grab SMTP banners", "brute force email credentials", or "assess mail server security". It provides comprehensive techniques for testing SMTP server security.

NewMaintained

Automatic

Security & AppSec pack

Last verified 8/30/2026

What it changes

Passed 11 of 22 test cases with the skill, and 11 of 22 without it.

Without skill50%

With skill50%

Checks it passed that the model alone missed

Issues EHLO or HELO command to prompt server banner response.

1 fixed19 passed either way2 still failing0 broke

Pass-rate lift: 0 pp
Tokens: +21%
Agent turns: 0%
Response time: +0%

Model gemini-3.6-flashMeasured 8/30/2026v120 of 22 cases passed with skill

Tokens, turns and time describe resource use, not a dollar price.

Use this skill

Save it into your project's skills folder. Claude Code picks it up in its next session.

curl -fsSL --create-dirs -o .claude/skills/dokhacgiakhoa-smtp-penetration-testing/SKILL.md https://app.decimal.ai/s/dokhacgiakhoa-smtp-penetration-testing/SKILL.md

Want it pinned and updatable? pip install "decimalai>=0.15", then decimalai skills add dokhacgiakhoa-smtp-penetration-testing, and start Claude Code with claude --plugin-dir "$(git rev-parse --show-toplevel)/.agents"

1 · One-time — install the CLI (docs ↗)

pip install "decimalai>=0.15"

2 · Get the skill — writes .agents/skills/dokhacgiakhoa-smtp-penetration-testing/ and pins it in .decimal/skills.lock

decimalai skills add dokhacgiakhoa-smtp-penetration-testing

No CLI? Get the same file — curl · raw file

curl -fsSL --create-dirs -o .claude/skills/dokhacgiakhoa-smtp-penetration-testing/SKILL.md https://app.decimal.ai/s/dokhacgiakhoa-smtp-penetration-testing/SKILL.md

Raw file: /s/dokhacgiakhoa-smtp-penetration-testing/SKILL.md ↗ · machine-readable summary at /s/dokhacgiakhoa-smtp-penetration-testing.json ↗

Safety checks: 3 of 3 passed

Code scan CleanIntent PassedContent Clean

See it in action

A test case the skill fixed. Same model, same prompt, with and without the skill.

Prompt

We need to identify the software version of an exposed email gateway running on port 25 without generating heavy network traffic. What is the standard manual command-line method to connect directly and retrieve the greeting header?

What was checked, without and with the skill
Checked	Without skill	With skill
Specifies connecting to port 25 using netcat or telnet.	Passed	Passed
Issues EHLO or HELO command to prompt server banner response.	Missed	Passed

case-02 · gemini-3.6-flash · 8/30/2026 · answers are capped and redacted

What's inside

The instructions your model reads when the skill loads.

SKILL.md34 linessingle file

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

🧠 Knowledge Modules (Fractal Skills)

1. Required Tools

2. Required Knowledge

3. Required Access

4. Phase 1: SMTP Architecture Understanding

5. Phase 2: SMTP Service Discovery

6. Phase 3: Banner Grabbing

7. Phase 4: SMTP Command Enumeration

8. Phase 5: User Enumeration

9. Phase 6: Open Relay Testing

10. Phase 7: Brute Force Authentication

11. Phase 8: SMTP Command Injection

12. Phase 9: TLS/SSL Security Testing

13. Phase 10: SPF, DKIM, DMARC Analysis

14. Essential SMTP Commands

15. SMTP Response Codes

16. Enumeration Tool Commands

17. Common Vulnerabilities

18. Legal Requirements

19. Technical Limitations

20. Ethical Boundaries

21. Example 1: Complete SMTP Assessment

22. Example 2: User Enumeration Attack

23. Example 3: Open Relay Exploitation

24. For Administrators

Track record

Benchmark

11 / 22

test cases passed, vs 11 / 22 without

Adoption

Users: 0
Times used: 0

Safety and source details

SkillSafety

✓ 3 of 3 passed

Code scan15 of 15 checks clean

0 critical · 0 warning · 0 info — scanner v4 — 8/10/2026

View 15 scanner checks

live_secretremote_code_executionreverse_shelldata_exfiltrationssrf_metadataagent_snoopinganti_refusaldestructive_commandsobfuscated_unicodeunicode_homoglyphopaque_blobsuspicious_urltool_overreachtrigger_abuseprompt_injection_phrasing

IntentSafe

LLM judge · does the skill do what it claims

ContentClean

LLM judge · policy & harmful-content review

Source

Imported

dokhacgiakhoa / agent-skills-4-vibe-coding-cli

.agent/skills/smtp-penetration-testing/SKILL.md

View on GitHub ↗

License NOASSERTIONImported 8/10/2026Version v1

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Ready to supercharge your AI agents?

See it in action

What's inside

SMTP Penetration Testing

Purpose

Prerequisites

🧠 Knowledge Modules (Fractal Skills)

1. Required Tools

2. Required Knowledge

3. Required Access

4. Phase 1: SMTP Architecture Understanding

5. Phase 2: SMTP Service Discovery

6. Phase 3: Banner Grabbing

7. Phase 4: SMTP Command Enumeration

8. Phase 5: User Enumeration

9. Phase 6: Open Relay Testing

10. Phase 7: Brute Force Authentication

11. Phase 8: SMTP Command Injection

12. Phase 9: TLS/SSL Security Testing

13. Phase 10: SPF, DKIM, DMARC Analysis

14. Essential SMTP Commands

15. SMTP Response Codes

16. Enumeration Tool Commands

17. Common Vulnerabilities

18. Legal Requirements

19. Technical Limitations

20. Ethical Boundaries

21. Example 1: Complete SMTP Assessment

22. Example 2: User Enumeration Attack

23. Example 3: Open Relay Exploitation

24. For Administrators

Track record

Benchmark

Adoption

SkillSafety

Source

Other skills for the same job

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