Email Header Analyzer
Paste your raw email headers to instantly decode routing hops, authentication results (SPF, DKIM, DMARC), spam scores, and delivery timestamps — all in a clean visual layout.
In Gmail: open email → ⋮ → "Show original" → copy all text above the dashed line. In Outlook: File → Properties → Internet Headers box.
View Raw Headers
Email headers contain a detailed log of every server your message passed through, including spam scores, authentication checks, and delivery timestamps — but they're notoriously hard to read in raw form. Paste your headers below and Flipper File will decode them into a clean, visual breakdown in seconds. No login, no account, and your header data never leaves your browser.
How to Analyze Email Headers
- Open your email client and find the option to view the raw or original message source. In Gmail, click the three-dot menu on any email and choose "Show original." In Outlook, open the message, go to File → Properties. In Apple Mail, go to View → Message → All Headers.
- Select and copy all of the header text — everything above the email body, starting with lines like
Received:,From:,Subject:,DKIM-Signature:, etc. - Paste the headers into the text box on this page and click Analyze Headers.
- Review the decoded output — routing hops are shown in order, authentication results (SPF, DKIM, DMARC) are highlighted pass/fail, and timestamps show delivery delays between servers.
- Use the results to diagnose delivery problems, identify spam filter triggers, or verify your email authentication is configured correctly.
Why Use Flipper File to Analyze Email Headers?
- Visual routing map — See every server hop in a clean, numbered timeline instead of wading through raw text
- Authentication at a glance — SPF, DKIM, and DMARC results are color-coded pass/fail so you can spot deliverability problems instantly
- Spam score extraction — Where present, spam assessment scores from filters like SpamAssassin are pulled out and displayed clearly
- Timestamp delay calculator — Delivery time between each hop is calculated automatically so you can spot where delays occurred
- Completely private — All analysis runs in your browser; your email headers are never sent to any server
- Free with no account — No login, no email address, no subscription required
Frequently Asked Questions
What are email headers?
Email headers are hidden metadata attached to every email message. They record the path the email traveled through mail servers, authentication checks performed along the way, spam filter verdicts, and timestamps for each step. They're essential for diagnosing email delivery problems but are hidden from view in most email clients by default.
How do I find raw email headers in Gmail?
Open the email in Gmail, click the three-dot menu in the top-right corner of the message, and select "Show original." A new tab will open showing the full raw message. Copy everything in the "Message headers" section at the top.
How do I find email headers in Outlook?
Open the email, click File → Properties. The headers appear in the "Internet headers" box at the bottom. Select all and copy.
What is SPF and why does it matter in headers?
SPF (Sender Policy Framework) is a DNS record that specifies which mail servers are authorized to send email on behalf of a domain. When an email arrives, the receiving server checks whether the sending server's IP matches the domain's SPF record. A fail result means the email may be flagged as spam or rejected entirely.
What is DKIM and how do I check if it passed?
DKIM (DomainKeys Identified Mail) adds a cryptographic signature to outgoing emails. The receiving server verifies this signature against a public key published in DNS. A DKIM pass in the headers means the email content wasn't altered in transit and the domain identity is verified. Look for a DKIM-Signature header and an Authentication-Results line showing dkim=pass or dkim=fail.
What is DMARC and what does it do?
DMARC (Domain-based Message Authentication, Reporting & Conformance) builds on SPF and DKIM by telling receiving mail servers what to do when either check fails — either nothing, quarantine the email, or reject it. The DMARC result in headers will show pass, fail, quarantine, or reject.
Can I use this to trace where spam came from?
Yes. The routing hops in analyzed headers show you every server the email passed through. The originating IP address (the first Received: line reading from bottom to top) is where the email actually came from, which you can then cross-reference with IP lookup tools to identify the sending location and organization.
Is my email content visible when I paste headers?
No. Email headers are separate from the email body. When you copy headers using the "Show original" or "View source" method in your email client, you're copying only the routing and metadata information — not the message body, attachments, or any private content.