# Mail Header Analyzer

> Analyze email headers in your browser: parse RFC 5322 headers, visualize the delivery route, check SPF/DKIM/DMARC — your start for manual, examples, tips.

Source: https://www.jpkc.com/db/en/tools/mail-header/

## Make email headers readable — without anything leaving your browser

Every email drags along a block of technical headers that most clients keep hidden: where the message came from, which servers it passed through, whether it could prove it wasn't forged, and whether a spam filter flagged it. The [Mail Header Analyzer](https://www.jpkc.com/tools/mail-header/) makes exactly that block visible. You paste the raw headers, click **Analyze**, and the tool breaks them down into four readable views: the key fields at a glance, the delivery route as a timeline, the authentication results, and a searchable table of every header.

The key point: the whole analysis runs **client-side, in your browser**. No server ever sees your headers — and email headers in particular tend to carry sensitive details: internal server names, IP addresses, recipient addresses, subject lines. That none of it is uploaded is not a side effect here, it's the whole idea.

The tool is built for anyone who needs to get to the bottom of an email: **admins and mail operators** tracing why a delivery is stalling; **developers** checking their SPF, DKIM, and DMARC setup against real headers; **support and security teams** dissecting a suspicious phishing message; and anyone who simply wants to know why a message landed in spam or arrived hours late.

## What the Mail Header Analyzer does — at a glance

- **Parse** — paste raw headers, upload a `.eml` or `.txt` file, or drop one in; **Analyze** gets you going.
- **Overview** — the central fields (From, To, Subject, Date and more) as a compact table, plus an authentication summary.
- **Route** — the delivery path from the `Received` headers as a timeline from sender to recipient, including waiting times, TLS status, and total transit time.
- **Security** — SPF, DKIM, and DMARC as result cards, plus a spam analysis built from the `X-Spam-*` headers.
- **All Headers** — every single header in a searchable table, with copy and download functions.

## Architecture: 100% in the browser, no backend

The Mail Header Analyzer has **no server component**. Parsing, route computation, authentication evaluation, and rendering all happen entirely in JavaScript in your browser. There is no API, no upload endpoint, no server-side caching. Even the file upload and drag-and-drop read the file locally through the browser's `FileReader` API — the file is never sent anywhere.

Because email headers can contain personal and confidential data, that's a real privacy advantage over many online header analyzers that ship your headers to a third-party server. One caveat: analyzed headers are stored in a **local history** within the tool (in your browser) so you can restore them after a reload — that, too, never leaves your machine. Details are in the [manual](https://www.jpkc.com/db/en/tools/mail-header/manual/#operating-limits-and-privacy).

## Try it now

**[→ Open the Mail Header Analyzer](https://www.jpkc.com/tools/mail-header/)** — paste headers, click *Analyze*, done. No account, free, right in the browser. If you don't have a real email handy, the **Example** button loads a realistic sample header to play with.

## Related JPKCom tools

- **[DNS, SSL, Redirect & URL](https://www.jpkc.com/db/en/tools/dns-ssl-redirect-url/)** — check the DNS records behind SPF, DKIM, and DMARC once the analyzer points to a problem.
- **[IP tools](https://www.jpkc.com/db/en/tools/ip/)** — look up and place a sender or relay IP pulled from the `Received` lines.
- **[Hash generator](https://www.jpkc.com/db/en/tools/hash/)** — compute checksums, for instance to compare a downloaded header file against the original.

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There's more on the sub-pages: the **[manual](https://www.jpkc.com/db/en/tools/mail-header/manual/)** with every tab and parsing rule, real-world **[examples](https://www.jpkc.com/db/en/tools/mail-header/examples/)**, and collected **[tips & tricks](https://www.jpkc.com/db/en/tools/mail-header/tips/)**.