What are Email Headers?

Email headers are the hidden part of an email that contains essential information about the email's origin, path, and delivery. While the email's content is visible to the recipient, the email headers are typically hidden and can be accessed by viewing the email's source or message properties. Email headers consist of several key components, including:

  • From: The sender's email address
  • To: The recipient's email address
  • Date: The date and time when the email was sent
  • Subject: The subject line of the email
  • Return-Path: The email address to which bounce notifications are sent
  • Received: A series of entries indicating the servers through which the email passed during transmission

Why is Email Header Verification Important?

Email header verification plays a crucial role in ensuring email authenticity, preventing spam, and identifying potential security threats. Here are some reasons why email header verification is important:

  • Identifying Spoofed Emails: Email headers provide information about the email's origin, allowing you to verify if the sender is genuine or if the email has been forged or spoofed.
  • Preventing Phishing Attacks: By analyzing email headers, you can identify signs of phishing attempts, such as mismatched domain names or suspicious routing information.
  • Checking SPF, DKIM, and DMARC: Email headers contain information related to SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting, and Conformance), which are email authentication mechanisms used to prevent email spoofing and improve email deliverability.
  • Detecting Spam: Email headers provide insights into the email's route and delivery, allowing you to identify characteristics commonly associated with spam emails.
  • Investigating Security Incidents: In the event of a security incident or email-based attack, analyzing email headers can provide valuable information to trace the source, track the path of the email, and identify potential vulnerabilities.

How to Analyze Email Headers

Analyzing email headers requires a basic understanding of the email header structure and the ability to interpret the information provided. Here are the key steps to analyze email headers:

  1. Access the Email Header: Depending on your email client, you can access the email header by viewing the email's source, message properties, or specific options provided by your email client.
  2. Review the "Received" Entries: The "Received" entries in the email header provide a chronological list of servers through which the email passed during transmission. Start from the bottom and work your way up to trace the email's path.
  3. Verify Sender Information: Check the "From" and "Return-Path" fields to verify the sender's email address. Pay attention to any discrepancies or inconsistencies that may indicate spoofing or phishing attempts.
  4. Check Authentication Mechanisms: Look for SPF, DKIM, and DMARC entries in the email header. Ensure that these mechanisms are properly configured and aligned with the sending domain to enhance email security.
  5. Identify Suspicious Patterns: Look for anomalies or suspicious patterns in the email header, such as unexpected routing, multiple "Received" entries from unfamiliar servers, or unusual timestamps.
  6. Compare with Known Information: Compare the information in the email header with known details, such as the sender's email address, domain names, or server configurations. Any discrepancies should be thoroughly investigated.

Commonly Asked Questions about Email Header Verification

1. Can email headers be modified or forged?

Yes, email headers can be modified or forged by malicious actors. However, thorough analysis and verification of email headers can help identify signs of tampering or spoofing.

2. Are email headers visible to the recipient?

Email headers are typically hidden from the recipient and can be accessed by viewing the email's source or message properties. Most email clients provide options to view the full email header.

3. How can I prevent email spoofing?

Implementing email authentication mechanisms like SPF, DKIM, and DMARC can significantly reduce the risk of email spoofing. These mechanisms help verify the authenticity of the email sender and detect forged or modified messages.

4. What tools are available to analyze email headers?

Several online tools and services are available to analyze email headers. These tools provide detailed insights into the email's origin, routing, and authentication status. Some popular tools include MXToolbox, Google Message Header Analyzer, and Microsoft Message Analyzer.


Email header verification is a critical aspect of email security. By understanding the structure and components of email headers and analyzing them effectively, you can identify potential security threats, prevent spam, and ensure email authenticity. Make email header verification a standard practice in your email security strategy and use the insights gained from header analysis to protect yourself and your organization from email-based attacks!