Email Header Analyzer
Paste raw email headers to analyze the routing path, SPF/DKIM/DMARC authentication results, delivery delays and more.
What is Email Header Analyzer?
Email headers are a detailed log of an email's journey from the sender's mail server to your inbox. They contain metadata about every mail transfer agent (MTA) that handled the message, timestamps at each hop, authentication results, and spam scoring decisions. While this information is invaluable for diagnosing delivery problems, the raw format is cryptic and difficult to read without a dedicated tool.
This email header analyzer parses raw email headers and presents the information in a clear, structured format. You can see the full routing path of the message hop by hop, the delay introduced at each transfer, SPF (Sender Policy Framework) verification results, DKIM (DomainKeys Identified Mail) signature validation, and DMARC policy outcomes — the three authentication mechanisms that determine whether an email is trusted by receiving servers.
Email headers are the first place to look when an email lands in spam, bounces unexpectedly, or arrives with an unusual delay. SPF failures indicate the sending server is not authorised to send on behalf of the domain. DKIM failures suggest the message was modified in transit or the key is misconfigured. DMARC failures mean the domain owner's policy was not satisfied, which often triggers spam classification. By decoding this information visually, the tool helps email administrators, developers, and technically curious users understand exactly what happened to a message and where any problems originated.
How to Use Email Header Analyzer
- Copy the raw email headers
In your email client, open the original message source or "Show headers" option and copy the full raw header text.
- Paste into the analyzer
Paste the copied headers into the text area. The analyzer accepts headers from Gmail, Outlook, Apple Mail, and most other clients.
- Run the analysis
Click Analyze to parse the headers. The tool extracts routing hops, timestamps, and authentication results automatically.
- Review the breakdown
See the full routing path, per-hop delays, SPF/DKIM/DMARC pass or fail status, and the originating IP address.
Key Benefits
See every mail transfer agent that handled your email, in order, with timestamps and delays at each hop.
Authentication results are parsed and displayed with clear pass/fail indicators so you can diagnose deliverability issues instantly.
Timestamps between hops reveal exactly where a slow delivery occurred — whether at the sender, an intermediate relay, or the recipient server.
Email headers are parsed entirely in your browser. Your message headers are never sent to or stored on any server.
Frequently Asked Questions
Open the email, click the three-dot menu in the top right corner of the message, and select "Show original". The raw headers appear at the top of the page that opens.
SPF failure means the sending mail server's IP address is not listed in the domain's SPF DNS record as an authorised sender. This is a common reason emails are marked as spam or rejected.
DKIM adds a cryptographic signature to outgoing emails, allowing the recipient's server to verify the message was not altered in transit and genuinely came from the claimed domain. A DKIM failure suggests tampering or a misconfigured key.
Email headers do not contain the body or attachments of your email — only routing metadata, server names, and authentication results. However, they can reveal sender IP addresses and internal server names, so exercise judgement for sensitive correspondence.