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Email validation, breach check, and associated account discovery

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SKILL.md

name Email Address Lookup
description Email validation, breach check, and associated account discovery
allowed-tools src.tools.email_lookup

Email Address Lookup

Purpose

Investigate email addresses for validation, security breach exposure, associated online accounts, and risk assessment for fraud prevention and due diligence.

When to Use

  • Email address validation and verification
  • Security breach exposure assessment
  • Account takeover and credential stuffing risk analysis
  • Due diligence on provided contact information
  • Investigation of suspicious email communications
  • Identity verification and authentication
  • Discovery of associated online accounts and services
  • Fraud prevention for email-based authentication

How to Use

The email lookup tool provides comprehensive email intelligence:

  • Validation: Syntax validation, domain verification, deliverability check
  • Breach Exposure: Known data breaches, credential leaks, password exposure
  • Account Discovery: Associated social media, shopping, professional accounts
  • Domain Analysis: Email provider, custom domain investigation
  • Risk Assessment: Disposable email detection, fraud indicators
  • Reputation: Spam history, blacklist status, trust indicators

Examples

Account security assessment:

Email: john.doe@company.com
Investigation: 3 known breaches, LinkedIn and Adobe data exposures
Risk: High - credentials likely compromised, recommend password reset

Business email verification:

Contact: info@newclient.com provided for partnership
Validation: Valid domain, corporate email server, established domain age
Assessment: Low risk - legitimate business communication

Fraud investigation:

Suspicious Email: temp123@10minutemail.com used in transaction
Analysis: Disposable email service, auto-expires, high fraud risk
Evidence: Consistent with fraudulent account creation patterns

Digital footprint analysis:

Subject: sarah.johnson@gmail.com in due diligence
Discovery: Associated Twitter, Facebook, LinkedIn accounts found
Intelligence: Cross-platform activity pattern analysis

Important Notes

  • Email breach data should be handled sensitively and legally
  • Disposable email services indicate higher fraud risk
  • Corporate emails generally have higher trust levels than free providers
  • Consider email domain age and reputation in risk assessment
  • Some email providers have enhanced privacy protections
  • Cross-reference email findings with other digital footprint data
  • Be aware of GDPR and privacy laws when collecting email intelligence
  • Email validation doesn't guarantee the email belongs to claimed owner
  • Consider social engineering risks when contacting discovered accounts