Email Header Analyzer
VerifiedPaste email headers to see SPF, DKIM, DMARC results explained in plain English
Product preview
Email Header Analyzer
What it is
Email Header Analyzer is a free tool from MailBoxInsights, an email-focused site run by an Exchange and Microsoft 365 specialist. You paste a message's raw headers and the tool checks SPF, DKIM, DMARC and Microsoft compauth, decodes Microsoft 365 spam stamps such as SCL, BCL and filter verdicts, and lists each delivery hop with its delay. It also flags warning signs like Reply-To mismatches. The checks themselves run in code, and AI turns the results into a plain-English explanation. It helps anyone working out why a message landed in junk, arrived late or looks like phishing, and the page includes steps for copying headers from Outlook and Gmail.
Key features
- SPF, DKIM, DMARC and compauth checks
- Microsoft 365 spam stamp decoding
- Delivery hop and delay map
- AI plain-English summary
What we liked
- + Free with no signup
- + Deterministic checks with AI only for explanation
- + Strong Microsoft 365 detail
Worth noting
- · Requires copying raw headers manually
- · Less tailored to non-Microsoft mail systems
Editor's notes
More context from AI BirdView
Email headers are full of useful clues, but they are notoriously hard to read. This analyzer splits the work sensibly: code performs the actual authentication and routing checks, and AI is used only to explain what those results mean, which keeps the verdicts grounded while making them understandable for non-specialists.
- Checks SPF, DKIM, DMARC and Microsoft compauth in one pass.
- Decodes Microsoft 365 stamps, including SCL, BCL, spam category and filter verdict.
- Maps every delivery hop with its delay, which helps explain late messages.
- Flags warning signs such as a Reply-To that does not match the sender.
- The site says nothing you paste is stored, and it is not affiliated with Microsoft.
It is best for IT admins, help desk staff and small business owners troubleshooting junked or suspicious mail, especially in Outlook and Microsoft 365. The same site also offers an AI Outlook rule builder and an out-of-office generator. A practical tip: compare headers from a message that arrived correctly with one that went to junk, since the differences in authentication and spam scores usually point straight to the cause.
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