Email Header

An Email Header is a crucial component of an email message that contains essential metadata about the email. This metadata includes information such as the sender, recipient, subject, and the path the email took to reach its destination. Understanding email headers is vital for troubleshooting email delivery issues, verifying the authenticity of an email, and ensuring email security.

Purpose of Email Headers

Email headers serve several important purposes:

• Routing Information: Email headers contain details about the servers and IP addresses involved in the delivery of the email, helping to trace its path from sender to recipient.
• Authentication: Headers include authentication results such as SPF, DKIM, and DMARC, which help verify the legitimacy of the email sender and prevent phishing attacks.
• Debugging: When email delivery issues arise, headers provide valuable information for diagnosing and resolving problems.
• Filtering: Email clients and servers use header information to filter and categorize emails, ensuring they are delivered to the appropriate folders.

How Email Headers Work

Email headers are automatically generated by email servers and clients during the sending and receiving process. They are typically hidden from the average user but can be viewed through email client settings. Here is a breakdown of how email headers work:

Field	Description
From	Indicates the sender’s email address.
To	Specifies the recipient’s email address.
Subject	Contains the subject line of the email.
Date	Shows the date and time the email was sent.
Received	Lists the servers through which the email passed, in reverse order.
Return-Path	Indicates the address to which non-delivery notifications should be sent.
Message-ID	A unique identifier for the email message.

Best Practices for Email Headers

To ensure effective use of email headers, consider the following best practices:

• Regularly Review Headers: Regularly review email headers to monitor for any unusual or unauthorized activity.
• Implement Authentication Protocols: Use SPF, DKIM, and DMARC to authenticate emails and protect against spoofing.
• Educate Users: Train users on how to view and interpret email headers to recognize phishing attempts.
• Use Consistent Formatting: Ensure that email headers are consistently formatted to facilitate easy analysis and troubleshooting.

FAQs

Related Terms

• SPF (Sender Policy Framework)
• DKIM (DomainKeys Identified Mail)
• DMARC (Domain-based Message Authentication, Reporting & Conformance)
• Phishing