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email-domain-security

Rigorous, defensible email-spoofability verdict and SPF supply-chain risk analysis computed from published DNS alone. Deepens the record-level SPF/DMARC/DKIM/BIMI/MTA-STS/DNSSEC fetch recipes in the offensive-osint arsenal (§16.14) with the reasoning that section doesn't do: a priority-ordered composite verdict for whether an attacker can actually land header-From-spoofed mail in an inbox, and by which vector (exact-domain vs subdomain) — grounded in the single most-misunderstood distinction in email security: the envelope MAIL FROM that SPF authenticates vs the visible header From: that only

Scanned · 1 to knowSkillSource: GitHub

2,831 stars +27 this week Updated 26d ago License MIT Context ≈156 tokens always loaded

74popular

Why this score

Stars

17/35

Usage (forks)

7/15

Upkeep

25/25

License

15/15

Owner history

10/10

This repo hosts 10 skills, so its 2,831 stars are split between them (about 283 each) for scoring.

Popularity score: 74/100 from public GitHub signals only. It shows how widely used and maintained this is, not how well it works. Not included yet: the fake-star check. The security scan is shown separately and doesn't change the score. How we rank

Security

Scanned Oct 20, 2026 at commit 114e0bb90e47, with Cisco's open-source skill-scanner.

What its code does:

Runs shell commands Common for dev tools. Read the commands it runs.SKILL.md:331 and 1 more

A scan lists patterns in the code. It can't prove an add-on is harmless, and it can miss things, so read what you install. How we scan

Alternatives

Other makers' add-ons that do the same job, next to this one.

Name	Score	Stars	Context	Updated
This oneemail-domain-security elementalsouls/Claude-OSINT · Skill	74	★ 2.8k	≈156 always	26d ago
email-writing Shy2593666979/AgentChat · Skill Both about email	71	★ 920	≈15 always	18d ago
email countbot-ai/CountBot · Skill Both about email	68	★ 784	≈20 always	25d ago
Domain Intelligence osiris-technical-institute/domain-intelligence-api · MCP server Both about domain and dmarc	53	★ 15	not measured	1mo ago
send-email google-ai-edge/gallery · Skill Both about email	84	★ 25k	≈6 always	16d ago
e2a — email for AI agents tokencanopy/e2a · MCP server Both about email and dkim	63	★ 198	not measured	2d ago

Install

mkdir -p .claude/skills/email-domain-security

curl -sL https://codeload.github.com/elementalsouls/Claude-OSINT/tar.gz/114e0bb90e47f01e64dc72d1f00b4221e0dde875 | tar -xz -C .claude/skills/email-domain-security --strip-components=3 "Claude-OSINT-114e0bb90e47f01e64dc72d1f00b4221e0dde875/skills/email-domain-security"

To remove it later:

rm -rf .claude/skills/email-domain-security

npx skills add elementalsouls/Claude-OSINT --skill email-domain-security

Pinned to commit 114e0bb90e47 as listed by GitHub.

Context cost: ≈156 tokens loaded every session (name and description), plus ≈12k tokens when the skill is used.

The Claude Code command downloads this skill folder at the pinned commit into .claude/skills/. The Skills CLI (npx skills) works with many agents but can't pin a version, so it installs whatever is current.

Used for

Security › Security review Operations › Email, chat & calendar

Facts

Repo: elementalsouls/Claude-OSINT
Stars: 2,831
Forks: 520
Last push: 2026-10-09 (26d ago)
License: MIT
Owner: elementalsouls · since 2019
Language: Python
Works with: Claude Code, Skills CLI