Email Header Analyzer
What Is an Email Header Analyzer?
An email header analyzer parses the raw headers of an email message to extract and visualize the delivery path, timing information, and authentication results. Every email contains headers that record which servers handled the message, when each server processed it, and what authentication checks were performed. This information is invaluable for troubleshooting delivery delays, identifying the source of spam, and verifying email authentication.
The most important headers for delivery analysis are the "Received" headers. Each mail server that processes an email prepends a Received header with the server's hostname, the previous server's hostname, a timestamp, and the protocol used. By reading these headers from bottom to top (oldest to newest), you can trace the complete path the email took from sender to recipient and calculate the delay at each hop.
Our analyzer parses all Received headers, extracts the "from" and "by" server names and timestamps, and calculates the time delay between consecutive hops. Long delays at a specific hop indicate a bottleneck - perhaps a server that was slow to process the message, a greylisting delay, or a spam filter that took extra time to analyze the content. The total delivery time is also calculated to give you an overall picture.
Beyond routing information, email headers contain authentication results. The Authentication-Results header shows whether the message passed SPF, DKIM, and DMARC checks. Headers like X-Spam-Score and X-Spam-Status reveal how spam filters rated the message. The DKIM-Signature header contains the cryptographic signature used to verify message integrity.
This tool runs entirely in your browser. Your email headers are never sent to any server - all parsing happens client-side in JavaScript. This means your potentially sensitive email data stays on your device. Paste the raw headers from any email client and get instant analysis without privacy concerns.
Frequently Asked Questions
What are email headers?
Email headers are metadata attached to every email. They contain sender/recipient information, the delivery path through mail servers, timestamps, and authentication results. Each server adds a Received header, creating a trace of the delivery route.
How do I find raw email headers?
In Gmail: three dots menu, then "Show original". In Outlook: File, Properties, Internet headers. In Apple Mail: View, Message, All Headers. The raw headers contain all routing and authentication information.
What do Received headers show?
Received headers trace the email's path from sender to recipient. Each server prepends a header with its hostname, the previous server, a timestamp, and protocol info. Read from bottom to top for chronological order.
How can headers help troubleshoot delivery problems?
Headers reveal where delays occur by showing timestamps at each hop. They also show authentication results (SPF, DKIM, DMARC), spam scores, and which servers handled the message, pinpointing exactly where issues occurred.