Get Important Email Info by Viewing the Entire Header

There's more to know than just subject line, sender, and date

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An email header contains the To and From email addresses, as well as the date and subject line. But, that's the tip of the iceberg. An entire email header contains much more information that can be valuable in certain situations, such as troubleshooting or avoiding scammers.

The Role of Email Headers

Every email consists of two parts: the header and the body of the message. Email headers include behind-the-scenes information that controls the transmission of the message and identifies metadata. In addition to the data you normally see, the header includes such information as the path the email takes, the servers it passes along the way, the time it does so, and the message priority.

Most people never need to view the entire header of an email. However, when troubleshooting an email problem, a technician may ask for the complete header for evaluation.

Additionally, header information can be used to identify a spam sender or verify that an email is a spoof or phishing attempt. Phishing attempts are malicious attacks that attempt to access private or sensitive information and give it to an individual masquerading as an authentic source (such as a bank or other financial institution). Examine the headers to identify these scams and keep yourself safe.

How to View an Email Header

Email headers are lengthy (sometimes longer than the body of the message) and complex. Most email clients and email web pages provide a way to display email headers. Each email program has its own method to view the entire header of a message. The instructions below show how to view the header in Gmail; check the documentation for other providers to learn how to view headers in those programs.

  1. Open a Gmail message.

  2. In the upper-right corner, select the menu (three-dot) icon, then choose Show original.

    Show original menu item in Gmail
  3. The header information appears in a separate window.

    Email header information
  4. The basic information appears at the top, followed by the full header at the bottom.

Understand an Email Header

Email headers appear as long complex blocks of text, but knowing what to look for can help you search them like a professional. Here's some of the information you'll find in an email header:

  • Content-Type: Notes whether the message is in HTML or plain text.
  • Date: When the message was composed.
  • Delivery Date: When the message was received by your mail server.
  • From: Who sent the message.
  • Received: All the servers the message was sent through.
  • Return-Path: Where a reply to the message will be sent.
  • Subject: The message subject.
  • To: Who the message was addressed to.
  • X-Originating-IP: The IP address from which the message was sent.
  • X-Spam: Spam information generated by your email service.

Email header information can be forged. In particular, the From field can be manipulated. Only sections containing the keyword Received should be fully trusted.