How to Access the Source for an Email Message in

Person at laptop

With, you can access the source for any email message and find out, for instance, what path it took to arrive in your account (using the headers) or what causes the left column to seem a wee bit off (using the HTML code).

Access the Source for an Email Message in

To view the full source behind an email in

  • Open the message whose source you want to open.
  • Click Actions in the message's top area (near the sender).
  • Select View message source from the menu that appears.

You can also get to a message's source view without opening the email itself first:

  • Click on the message in its folder's email list with the right mouse button.
  • Choose View message source from the context menu that shows.

Interpreting Message Headers

Message headers are hidden by default because most people have neither the need to inspect them nor the technical acumen to inspect them. Nevertheless, inspecting headers can lead to some valuable insights about a message.

  • Received—several different lines, each reflecting a mail server that processed the message on its journey from source to destination. Many different "received" lines suggest that the message took many different hops on its way to you.
  • Return-Path—the "reply to" address, which might be different from the "from" address.
  • Authentication-Results—reference to whether (or to what degree) the sender's email server verified the sender's credentials.
  • Date—the date the message was originally transmitted by the sender.
  • From—the email address, and often the display name, of the person who sent the message.
  • Reply-To—the address that will pop up if you click "reply" to the message. May not be the same as the address of the sender.
  • Message-ID—the "tracking number" of the email.
  • Precedence—a non-standard ranking system. A message listed as "bulk," for example, indicates it's a mass message. Different servers use it in different ways, and some don't use it at all.
  • List-Unsubscribe—a keyed reference so you can immediately unsubscribe from whatever mail list the message sourced from.
  • X-Spam-Score—a number, put on by your own mail server, identifying what it thinks the likelihood is that the message is spam. If the score falls above a given number, it may automatically route to your spam folder.

There are many different approved types of email headers, and many headers are either inconsistently used or controversial among the guardians of Internet standards. Despite the diversity of information you'll see in any given message's headers, these cryptic data points share much useful data about the message, its sender and its path to your inbox.