A free email header analyzer that traces an email's path, its SPF, DKIM and DMARC verdicts, and its unsubscribe headers.
5.0(1 rating)Paste an email's headers, or drop the .eml file. See every server it passed, how long each took, and how the receiver judged it.
Your email's headers
- Gmail – open the email, click the 3 dots next to Reply, then Show original.
- Outlook – open the email, click the 3 dots, then View and View message source.
- Apple Mail – open the email, then View, Message, All Headers.
- Yahoo Mail – open the email, click the 3 dots, then View raw message.
Your headers are read in your browser and never uploaded.
This free email header analyzer reads an email's headers the way the receiving server wrote them: every server it passed and how long each took, the SPF, DKIM and DMARC verdicts, and whether the From domain aligns.
It also checks the unsubscribe headers Gmail and Yahoo require from bulk senders, and the rules DNS alone can't show.
What is an email header analyzer?
An email header analyzer turns the raw headers at the top of every email, like Received, Authentication-Results and DKIM-Signature, into a readable trace and verdict.
Where to find an email's headers
| Email app | Where |
|---|---|
| Gmail | Open the email, the 3 dots next to Reply, Show original |
| Outlook | Open the email, the 3 dots, View, View message source |
| Apple Mail | View, Message, All Headers |
| Yahoo Mail | Open the email, the 3 dots, View raw message |
Copy the headers from the recipient's copy: an email in your Sent folder has no verdicts yet.
What the headers tell you
| Header | What it says |
|---|---|
| Received | Each server the email passed, newest first, with the time |
| Authentication-Results | The receiver's SPF, DKIM and DMARC verdicts |
| DKIM-Signature | Who signed it (d=) and with which key (s=) |
| Return-Path | Where bounces go, the domain SPF checks |
| List-Unsubscribe | The unsubscribe link or address |
| List-Unsubscribe-Post | One-click unsubscribe (RFC 8058) |
Alignment: why passing isn't enough
DMARC needs SPF or DKIM to pass for your From domain, not just any domain. An email from you@yourdomain.com sent by a service can pass SPF for the service's bounce domain and still fail DMARC.
The analyzer compares each passing check's domain with your From domain, and says which one aligns.
Final thoughts on email headers
Headers are the only place you see how a receiver judged a real email. When something lands in spam, start here.
Then check the sending domain with the email deliverability checker, and the sending IP with the email blacklist check.
Ready to send?
Email platforms that set up SPF, DKIM and DMARC with you
For developers: send from your own app
Where your domain and inbox live
Email Header Analyzer FAQs
Questions about email headers? Here's what to know.
An email header analyzer reads an email's headers and shows the servers it passed, how long each took, and its SPF, DKIM and DMARC verdicts.
Open the email, click the 3 dots next to Reply, and pick Show original.
It's the receiving server's verdict on the email: SPF, DKIM and DMARC, each a pass or a fail.
Read them from the bottom up: the lowest one is the first server, and the top one is the last.
The domain that passed SPF or DKIM must match your From domain, or share its organizational domain.
No, the analyzer reads them in your browser.
Yes, the email header analyzer is free, with no sign-up.
Navid Moazzez
AI business strategist & AI OS builder
Navid Moazzez helps creators and founders master AI and build their own AI Operating System (AI OS) to automate their business and life.
Navid.me is reader-supported. When you buy through links on this site, I may earn an affiliate commission. Learn more.
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