Email headeranalyzer.
Paste the headers of an email to see the route it took, where it was delayed, and how it did on SPF, DKIM and DMARC, so you can see why it went to spam.
How it works
- Copy the headers"Show original" in Gmail
- Paste them hereEverything above the message
- Read the verdictAuthentication, route and delays
Free, no sign-up. Runs in your browser. Nothing you type is sent anywhere.
The tool
Paste a message's headers
In Gmail: open the email, ⋮ then "Show original", and copy everything above the message. In Outlook: File, Properties, "Internet headers". Nothing leaves your browser.
Reading email headers.
What the result means, and how to fix what it finds.
Getting the headers
Every email carries a block of headers its readers never see. In Gmail, open the email, press the three dots and choose Show original. In Outlook, open it in a window and choose File, then Properties, and copy the Internet headers. In Apple Mail, choose View, Message, All Headers. Send a test email to yourself to check your own setup.
Authentication results
The receiving server writes down whether the email passed SPF, DKIM and DMARC. All three passing means the email is provably yours. A fail tells you which record to fix: SPF means the sending server isn't in your SPF record, DKIM means the signature is missing or broken, and DMARC means neither lined up with the From domain.
The route and delays
Each server that handles an email adds a Received line on top, so reading from the bottom shows the route from your mail server to the inbox. Large delays between steps usually mean a server deferred the email, which can be a sign of a reputation problem or of greylisting by the receiver.
When everything passes
If SPF, DKIM and DMARC all pass and the email still went to spam, the cause is reputation or content: a new domain without history, people ignoring or reporting your email, too many links or tracked links, or a list with many dead addresses. Warm up the mailbox, verify the list, and keep the email plain.
Spotting spoofed email
Headers also help when someone sends you email pretending to be a company you trust. Check the Authentication-Results line first: a real email from a large company passes DMARC. Then compare the From address with the Return-Path and the first Received line: a message claiming to be from your bank but sent from an unrelated server is fake, whatever the logo says. Look at the Reply-To too; scammers often set it to their own address so replies reach them. When in doubt, don't click links in the email: go to the company's website directly.
In mailzy
Know where your email lands.
mailzy shows inbox, spam and promotions rates for every mailbox, and a reputation label for each domain.
Questions before you start.
Ask us on the chat if yours isn't here. A real person answers.
Is it safe to paste my headers here?
Yes. The analyzer runs in your browser and nothing is sent to us. Headers do contain email addresses and server names, so avoid pasting them into tools that upload them.
Why don't I see DMARC results?
Some receivers don't write them down. Gmail and Outlook do; test by sending to a Gmail address.
What's a good delivery time?
A few seconds. Minutes or hours usually means a server deferred the email and tried again.
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