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Email Header Analyzer

Paste the raw headers of an email to see each server it passed through, how long each hop took and whether it passed authentication.

About Email Header Analyzer

An email header analyzer answers what the inbox hides: why an order confirmation went to a customer's spam folder, where a message sat for two hours, or whether a mail from "your CEO" really came from your company. Copy the full headers, using Show original in Gmail or the message source in Outlook, and paste them in. The Received lines become a delivery path, hop by hop, with the delay at each step and the total time.

You also get From, To, Subject, Date, Message-ID and Return-Path, the SPF, DKIM and DMARC results the receiving server wrote into Authentication-Results, the DKIM signing domain and selector, any spam-filter headers, and every header in a table. A DMARC fail on a message that claims to be from your bank is a strong warning sign. The analysis runs in your browser, so headers never leave your device. To check the published key, use the DKIM Checker.

How to use Email Header Analyzer

  1. 1
    Copy the full headers

    In Gmail choose Show original, in Outlook open the message source, then copy everything.

  2. 2
    Paste them in

    Paste the headers into the email header analyzer.

  3. 3
    Follow the path

    Read the hops from sender to inbox, with the delay at each one and the total time.

  4. 4
    Check authentication

    See the SPF, DKIM and DMARC results and which domain and selector signed the message.

Why use Cubfile for this

  • Hop-by-hop path

    Built from the Received lines, with the delay per hop and the total delivery time.

  • SPF, DKIM and DMARC results

    Read from Authentication-Results, along with the DKIM signing domain and selector.

  • Key fields first

    From, To, Subject, Date, Message-ID and Return-Path up front, then every header in a table.

  • Stays on your device

    Runs in your browser, and works offline once the page is loaded.

FAQ

Email Header Analyzer: questions and answers

How do I get the full headers of an email?
In Gmail, open the message, click the three-dot menu and choose Show original. In Outlook, open the message's More actions menu and choose View, then View message source or View message details. In classic Outlook for Windows, open the message and look under File, Properties, Internet headers.
Why is there a long delay between two hops?
Each delay is the gap between the timestamps of two Received lines. A long gap usually means a server held the message in a queue, for example while a spam filter scanned it or after a temporary error, and clocks that are slightly off can show odd or negative delays.
What does Authentication-Results tell me?
The verdicts the receiving server recorded at delivery, such as spf=pass, dkim=pass and dmarc=pass, with the domains they applied to. To check your records as they are now, use the SPF, DKIM and DMARC checkers.
Can the email header analyzer spot a phishing email?
It shows the evidence rather than a yes or no. A DMARC fail, a signing domain that doesn't match the From address, or a route through unrelated servers on a message claiming to be from your bank are strong warning signs. A WHOIS Lookup on the sender's domain shows how recently it was registered.
Are my email headers uploaded?
No. The analyzer runs in your browser, so the addresses and IPs in the headers stay on your device. It's free, needs no sign-up and doesn't count toward any limit.
Share Email Header Analyzer with a friendIt runs in any browser, and they can try it without signing up.

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