Email Header Analyzer
Parse and analyze raw email headers — decode routing, security checks, and metadata.
Email Header Analyzer — decode routing and security checks
Every email carries a set of headers that reveal its routing path, authentication results, and metadata. This tool parses raw email headers following RFC 5322 — including folded continuation lines — and groups them into logical sections. The Authentication-Results header is especially important: it records whether DKIM (cryptographic signature), SPF (sender IP authorization), and DMARC (policy enforcement) checks passed or failed. A failing DKIM or SPF check can indicate a forged sender or misconfigured email server. To find raw headers: in Gmail, open the email → More (⋮) → Show original; in Outlook, File → Properties → Internet headers; in Apple Mail, View → Message → All Headers.
Private & free — this tool runs entirely in your browser.