# Email Header Analyzer

> Free email header analyzer for SPF, DKIM, DMARC, Return-Path, DKIM d=, Authentication-Results, Received headers, and alignment review.

- Human page: https://mailrith.com/free-tools/email-header-analyzer
- Markdown page: https://mailrith.com/free-tools/email-header-analyzer.md
- Category: Email Authentication
- Action label: Analyze Headers
- Primary keyword: email header analyzer
- Related keywords: email header analyzer, analyze email headers, email authentication header checker, SPF DKIM DMARC header analyzer, message header analyzer
- Browser execution: Yes
- Signup required: No

## Input
- Label: Raw Email Headers
- Guidance: Use this after sending a real test email. Copy the original headers from the inbox and paste them here.
- Placeholder example: From: News <news@example.com> / Return-Path: <bounce.example.com> / Authentication-Results: mx.google.com; spf=pass smtp.mailfrom=bounce.example.com; dkim=pass header.d=example.com; dmarc=pass header.from=example.com / DKIM-Signature: v=1; d=example.com; s=selector1;

## How to Use
1. Open the human page: https://mailrith.com/free-tools/email-header-analyzer
2. Enter raw email headers using the guidance above.
3. Select Analyze Headers.
4. Review the status, checked facts, and next actions.
5. Use the linked guide section for any issue that needs a fix.

## Topic Overview
Email headers are the delivery receipt inside a message. They show which servers handled the email, which domains were used for SPF, DKIM, and DMARC, and what the receiving inbox decided during authentication. This analyzer turns raw header text into readable facts so you do not have to inspect every line manually. Use [Email Headers and Message Format](https://mailrith.com/guides/email-headers-and-message-format.md#steps) to understand the fields in context.

Headers are especially useful when an email lands in spam, fails DMARC, or behaves differently at Gmail, Outlook, or a company inbox. The analyzer can point to authentication results, forwarding behavior, return-path domains, and suspicious hops, but it still needs the full original header text from the received message. If the issue is alignment, read [DMARC Alignment](https://mailrith.com/guides/dmarc-alignment.md#steps) after reviewing the parsed results.

## What the Tool Checks
- From and Return-Path domains
- Authentication-Results for SPF, DKIM, and DMARC
- DKIM signing domain and selector clues
- Basic relaxed alignment review
- Received header count and routing clues
- Plain-English fixes for failed authentication

## Result Behavior
The result explains which authentication checks passed or failed in the real message and what to change next.

## AI Agent Notes
- Use this markdown page for retrieval, summarization, and deciding which tool to recommend.
- Use the human page when the user needs to run the checker interactively.
- Do not claim the tool sends emails unless the page explicitly says it does.
- When the result mentions a server-side confirmation, explain that the browser page can show public signals but cannot complete that network check by itself.

## Related Guides
- [Email Headers and Message Format](https://mailrith.com/guides/email-headers-and-message-format.md#steps): Learn what the important email headers mean.
- [DMARC Alignment](https://mailrith.com/guides/dmarc-alignment.md#steps): Compare From, DKIM, and SPF domains in real headers.
- [DKIM](https://mailrith.com/guides/dkim.md#steps): Understand DKIM signatures and signing domains.

## FAQs
### Where do I find original email headers?

In Gmail, open the message, use the three-dot menu, and choose Show original. Other inboxes usually call this view original, message source, or internet headers.
### Can this read private email safely?

The analyzer runs in your browser. Still, paste only the headers you need and remove message body content if it contains private information.