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what-an-email-reveals

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Investigate an email address — MX and syntactic validation, Gravatar lookup, corporate email-format inference, breach exposure, and full mail-header analysis covering the Received chain, Message-ID and SPF, DKIM and DMARC results. Use for email OSINT, verifying whether an address exists, finding accounts registered to it, guessing a company's email format, or tracing where a suspicious message actually came from. Applies to business email compromise and invoice-fraud investigation, phishing triage, vendor-payment verification, and pre-engagement research. Reference at useosint.com/skills/what-an-email-reveals.

skills/what-an-email-reveals/SKILL.md

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# What an email reveals

An email address is usually the highest-value selector in an investigation: it
carries a name, a domain, an account history, and a breach footprint. The
beginner error is trying to prove the address exists. Existence is the least
interesting thing about it, it is the hardest thing to establish passively, and
the techniques that establish it are the ones that expose you. Work the
structure and the footprint first; treat validation as a bonus.

Never send mail to the subject as a research technique.

## Step 1 — Authorized scope

Read [../../ETHICS.md](../../ETHICS.md). Write down subject, objective,
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