🔍 Free Security Tool

Email Header Analyzer

Paste the raw email header — SPF/DKIM/DMARC, Microsoft 365 antispam, phishing indicators and A-F security grade are automatically calculated.

💡 Gmail: Open email → ⋮ → "Show original" | Outlook: File → Properties → Internet headers

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What is SPF?

Defines which servers can send email for a domain. Without SPF, anyone can send email on your behalf.

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What is DKIM?

A cryptographic signature mechanism that verifies email content was not altered in transit.

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What is DMARC?

A policy record that determines what happens to an email when SPF and DKIM fail (reject/quarantine/none).

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Microsoft 365 SCL?

-1: Safe listed. 0-4: Clean. 5-6: Likely spam. 7-9: Definite spam/quarantine. Microsoft Exchange's internal scoring system.

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Phishing Detection

Reply-To ≠ From, Return-Path ≠ From domain mismatches and SPF/DKIM/DMARC failures are the main phishing indicators.

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What is a Hop Chain?

The server route of an email from source to destination. Each Received header represents a hop; many unknown hops may indicate spoofing.