ANALYZE YOUR EMAIL HEADERS
& DIAGNOSE DELIVERY ISSUES Decorative underline

Paste the raw headers from any email to instantly trace its delivery path, identify authentication failures, measure hop delays, and see spam scoring.

No account needed. Your headers are never stored. Results in seconds.

Please paste your full email headers (at least 50 characters).
How to get headers: Gmail → open email → More (⋮) → Show original  |  Outlook → File → Properties  |  Apple Mail → View → Message → All Headers
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What the Analyzer Extracts
  • ✓ Full hop-by-hop delivery path
  • ✓ Timestamp and delay per hop
  • ✓ SPF authentication result
  • ✓ DKIM signature verification
  • ✓ DMARC policy result
  • ✓ X-Spam-Score if present
  • ✓ Total delivery time
  • ✓ Sending and receiving servers

When Email Goes Wrong,
Headers Tell the Truth

Email headers are the flight recorder of every message. When an email lands in spam, arrives late, or disappears entirely, the headers contain the exact sequence of events from send to delivery - if you know how to read them.

Delivery tracing Trace exactly which servers handled your email and where delays occurred in transit
Auth diagnostics Diagnose SPF, DKIM, and DMARC failures at each hop - see exactly where authentication broke down
Spam scoring Find out if a spam filter scored your message and why - before you resend or escalate

Common Problems Headers Help Diagnose

  • ● Email landing in spam - authentication failures in Authentication-Results reveal whether SPF, DKIM, or DMARC caused the filter hit
  • ● Delayed delivery - comparing timestamps across Received headers shows exactly which hop introduced latency
  • ● Missing DKIM signature - if no DKIM-Signature header is present, the email is unsigned and more likely to be filtered
  • ● SPF alignment mismatch - the envelope From and the header From point to different domains, causing DMARC failure
  • ● High spam score - an X-Spam-Score of 5+ in the headers explains why legitimate email was sent to junk

What Makes DMARCFlow's Header Analyzer Different

Not just raw header display - structured diagnostics with plain-language explanations.

Hop visualization
Hop-by-Hop Path

Visual table showing each mail server the email passed through, with timestamps and delay calculations between hops.

Auth results
Auth Results

Parses Authentication-Results headers to show SPF, DKIM, and DMARC pass/fail status with clear explanations.

Spam score
Spam Score

Extracts and interprets X-Spam-Score and X-Spam-Status headers so you understand why an email was flagged.

Privacy safe
Privacy Safe

Headers are never permanently stored. Your data is processed only to generate the analysis and is then discarded.

Frequently Decorative underline Asked
Questions

Everything you need to know about email headers and delivery diagnostics

Email headers are metadata attached to every message that record its technical journey. They contain: the servers that handled the message (Received headers), authentication results (SPF, DKIM, DMARC), the original sender and recipient information, timestamps, message IDs, spam scores, and dozens of other fields added by mail servers along the delivery path. They are invisible to end users by default but accessible through any email client.

Gmail: Open the email, click the three-dot menu next to Reply, select "Show original". Copy everything in the popup window.

Outlook (desktop): Open the email, go to File → Properties. The headers are in the "Internet headers" box at the bottom.

Outlook (web): Open the email, click the three-dot menu, select "View message source" or "Show message details".

Apple Mail: Open the email, go to View → Message → All Headers. Or use View → Message → Raw Source.

Yahoo Mail: Open the email, click the three-dot menu, select "View Raw Message".

Received headers are added in reverse order — the first one at the top is the last server to handle the message (the recipient's inbox), and the last one at the bottom is the first server (the sender's mail server). To trace the path, read from bottom to top. Each header shows "from [server A] by [server B]" with a timestamp. Comparing timestamps between adjacent Received headers reveals where delays occurred.

The Authentication-Results header is added by the receiving mail server to record the results of SPF, DKIM, and DMARC checks for that message. Each check shows pass, fail, neutral, softfail, or none. A DMARC fail here tells you that neither SPF nor DKIM passed in alignment with the From: domain — this is often why messages land in spam or are rejected.

Email headers can contain IP addresses of your mail server, the recipient's mail server, your email client's IP (in some cases), sender and recipient email addresses, and the message ID. They do not contain the email body or attachments. Before sharing headers with any external tool, be aware that server IP addresses and internal routing paths may be sensitive for enterprise environments. DMARCFlow processes headers only for analysis and does not permanently store them.

DKIM (DomainKeys Identified Mail) adds a cryptographic signature to outbound email that the receiving server can verify using a public key published in your DNS. When DKIM passes, it proves the email content was not modified in transit and that the signing domain is authorized to send. Without DKIM, your email has no cryptographic proof of authenticity, making it more likely to fail DMARC and be filtered as spam.