Email Header Analyzer

Inspect raw email headers, trace SMTP relay hops, calculate network delivery latency, and audit SPF, DKIM, and DMARC security records.

📧 Email✉️ Email Tool⚡ Deliverability
Quick Overview & Direct Answer

Email Header Analyzer — Trace Mail Hops, MTA Delays & SPF/DKIM Auth: Free Email Header Analyzer tool: inspect raw email headers, trace SMTP relay hops, calculate network delivery latency, and audit SPF, DKIM, and DMARC.

Primary Use Digital productivity, instant calculation, and workflow acceleration
Input Formats Standard browser input parameters
Output Format Instant real-time output and downloadable results
Processing Mode 100% Client-Side or In-Memory Localized Processing
Access Tier Free, unlimited, no sign-up needed

How to Extract and Analyze Email Headers

1

Copy Raw Email Headers

In your email client (Gmail, Outlook, Apple Mail), click 'Show Original' or 'View Message Details' and copy the entire text header.

2

Paste into Header Analyzer

Paste the full header block into the analyzer box and click 'Analyze Email Headers'.

3

Trace Server Relay Hops

Review each intermediate Mail Transfer Agent (MTA) hop, TLS encryption ciphers, and delivery delays between servers.

4

Verify Authentication

Check SPF, DKIM, and DMARC status badges to verify whether the email was spoofed or authenticated legitimately.

The Anatomy of RFC 5322 Internet Message Headers

Every electronic mail message sent across the Internet consists of two core components: the header, containing structured transport instructions and cryptographic authenticity proofs; and the body, containing the text or HTML message content. While email clients hide technical headers from everyday users, these headers contain an unforgeable audit trail documenting the exact physical path the message took across global networks.

Core Email Header Fields Explained

Header Field Standard RFC Function & Security Importance
Received: RFC 5321 Prepended by each Mail Transfer Agent (MTA) along the relay route. Documented in reverse chronological order (bottom hop is origin, top hop is final recipient server).
Authentication-Results: RFC 8601 Records the receiving server's verdict on SPF validation, DKIM signature verification, and DMARC alignment compliance.
DKIM-Signature: RFC 6376 Contains the RSA/Ed25519 digital signature of the email body and critical headers, verified against public keys published in sender DNS records.
Return-Path: RFC 5321 The envelope sender address (SMTP MAIL FROM) where automated bounce notifications (NDRs) are directed.
Message-ID: RFC 5322 Globally unique string identifying the specific message instance, preventing duplicate deliveries and threading conversation chains.

Diagnosing Delivery Bottlenecks & Relay Latency

Email delivery should typically conclude in less than 5 seconds. However, misconfigured spam filtering proxies, greylisting daemons, or DNS lookup timeouts frequently introduce multi-hour relay delays. By calculating the difference between the timestamps recorded on consecutive Received: header lines, the Email Header Analyzer pinpoints the exact server node responsible for delivery latency.

Detecting Phishing, Spoofing, and Display Name Fraud

Cybercriminals routinely forge the user-facing From: display header to impersonate banks, CEOs, or service providers. Analyzing headers exposes this fraud immediately:

  • Mismatched Envelope Sender: If the user-visible From: claims to be security@paypal.com, but the Return-Path or origin hop points to an unauthorized IP range without SPF authorization, the message is fraudulent.
  • DKIM Domain Verification (d=): Cryptographic DKIM signatures specify the domain of the signing organization (d=domain.com). If an email claiming to originate from Google has a DKIM signature from an unknown third-party domain, it fails authentication alignment.
  • DMARC Alignment Failures: When both SPF and DKIM fail to align with the header From: address, DMARC-compliant mailboxes reject or quarantine the message before it reaches user inboxes.

Key Benefits of the Email Header Analyzer

MTA Relay Hop Visualization

Chronologically trace each intermediate mail server hop from the origin sending server to final delivery.

SPF, DKIM & DMARC Audit

Instant visual badges verify whether cryptographic digital signatures passed or failed mailbox validation.

Delivery Latency Detection

Calculates precise second-by-second delivery latency between relay servers to diagnose delayed emails.

Origin IP Address Extraction

Identifies the true sending IP address and mail client host before cloud relays mask the sender.

TLS Encryption Cipher Audit

Checks whether message transport was secured in transit using modern TLS 1.3 or unencrypted SMTP.

100% Client-Side Privacy

Confidential email headers and corporate server hostnames are parsed locally in browser memory without external tracking.

Frequently Asked Questions

How do I view email headers in Gmail?
Open the email in Gmail on your computer, click the three vertical dots (More options) next to the Reply button in the top right of the message, and select 'Show original'. Click 'Copy to clipboard' to copy the raw headers.
How do I view email headers in Microsoft Outlook?
In Outlook desktop, double-click the email to open it in its own window, go to File > Properties, and copy the text inside the 'Internet headers' box at the bottom. In Outlook Web, click the three dots > View > View message details.
What does 'Received: by' mean in email headers?
Every time an email moves from one mail server to another, the receiving server stamps a 'Received:' header at the top of the message. By reading these lines from bottom to top, you can trace the exact path the email took across the Internet.
What is the difference between SPF, DKIM, and DMARC?
SPF authorizes specific server IP addresses to send mail on behalf of a domain. DKIM attaches a cryptographic digital signature to verify the message wasn't tampered with in transit. DMARC ties SPF and DKIM together and instructs receiving servers how to handle emails that fail verification.
Are my email headers uploaded to any server?
No. All header parsing, regex extraction, hop latency calculations, and security auditing occur entirely inside your web browser via client-side JavaScript. Your headers are never sent over the Internet.

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