Email Header Analyzer
Inspect raw email headers to trace Received relay hops, calculate inter-hop transit delays, verify Authentication-Results (SPF, DKIM, DMARC), and flag suspicious security anomalies.
Interactive Workbench
Real-time processing directly in your browser.
Client-Side Email Header Parsing and Relay Chain Inspection
The Email Header Analyzer inspects raw email headers to trace message routing, evaluate transport delays, and verify authentication credentials. Operating 100% locally within your browser, security analysts, IT administrators, and email forensic investigators can analyze header payloads without exposing message content or user identities to remote servers.
This utility parses RFC 5322 header lines, extracts the full Received relay chain, calculates inter-hop transit delays, and inspects Authentication-Results headers for SPF, DKIM, DMARC, and Authenticated Received Chain (ARC) verification signals.
In addition, the workspace automatically flags suspicious security anomalies. such as Reply-To and From domain mismatches, duplicate header injections, and unusual transit delays. helping users detect spoofing attempts and malicious phishing campaigns.
Core Tool Capabilities
- Received Relay Chain Timeline: Reconstructs message transit hops from originating mail server to destination gateway, displaying timestamps and relay hostnames.
- Inter-Hop Transit Delay Calculation: Calculates precise processing delays between consecutive mail transfer agents (MTAs) to identify routing bottlenecks or delays.
- Authentication-Results Extraction: Extracts and categorizes SPF, DKIM, DMARC, and ARC verification statuses directly from gateway authentication headers.
- Security Anomaly and Spoof Detection: Detects domain mismatches between From and Reply-To headers, missing Message-IDs, and duplicate header injections.
Local Browser Privacy
Your files are processed locally on your device. Files are not uploaded, transmitted, or stored on remote servers.
Once the page has loaded, you can disconnect your network connection and continue using this tool offline.
Target Use Cases
- • Phishing and Email Forensic Analysis
- • Mail Delivery Troubleshooting
- • Email Authentication Audit
- • ESP Relay and Gateway Validation
Technical Specifications & Platform Limits
Standard internet message header specifications.
Deterministic client-side header unfolding and parsing.
Raw headers remain in volatile client memory.
Instant analysis with zero cloud dependency.
Step-by-Step Workflow
Copy Raw Email Headers
Open your email client (e.g. Gmail, Outlook, Thunderbird) and copy the complete raw message headers.
Paste Header Payload
Paste the raw header string into the analyzer input area or load the sample header preset.
Click Analyze Header Payload
Click Analyze Header Payload to trigger local browser parsing and anomaly detection.
Review Hops and Security Findings
Inspect the Received hop timeline, transit delays, Authentication-Results summary, and flagged security anomalies.
Practical Real-World Use Cases
Phishing and Email Forensic Analysis
Security incident responders analyzing suspicious email headers to identify spoofed senders and originating IP addresses.
Mail Delivery Troubleshooting
System administrators inspecting transit delay timestamps across relay servers to diagnose email delivery latency.
Email Authentication Audit
IT engineers verifying that receiving mail gateways correctly evaluate SPF, DKIM, and DMARC credentials.
ESP Relay and Gateway Validation
DevOps teams verifying that outgoing emails routed through transactional email services preserve proper Return-Path and DKIM signatures.
Frequently Asked Questions
- Are my pasted email headers stored on any server?
- No. All header parsing and anomaly detection occur 100% locally in your browser memory. No header data is ever transmitted over the network.
- Why does the Received chain list hops in reverse order?
- Each mail server that handles a message prepends its Received header at the top. As a result, the bottom-most Received header represents the originating server, while the top-most represents the final receiving gateway.
- What does a Reply-To mismatch indicate?
- When an email's From address uses one domain but the Reply-To address points to an unrelated domain, it often indicates a phishing attempt designed to redirect recipient replies to an attacker.
- How are transit delays between relays calculated?
- Transit delays are computed by calculating the difference between timestamps recorded in consecutive Received headers, accounting for timezones and flagging delays greater than five minutes.
- What is the purpose of the Authentication-Results header?
- The Authentication-Results header (RFC 8601) records the cryptographic verification outcomes for SPF, DKIM, and DMARC performed by the receiving message transfer agent.
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Master this tool with Guides & Articles
Learn the workflows, common mistakes, and advanced techniques behind Email Header Analyzer - Received Hop & Auth Inspection with our deep-dive educational content.