About email headers

 

An email message consists of two parts, the header fields and the body. The message body is the actual content of the message that was created by the sender, excluding the fields like "Subject", "To", and "CC". The header fields, which are often called just "headers", contain quite a bit of additional information that travels with the message. The headers are primarily meant to be used by the email software. However, they can also be useful for troubleshooting email problems or tracing spam and email viruses to their source. Therefore, if you would like to report an email problem, spam, or a message that's possibly infected with a virus, you should forward not only the message but also the full contents of the message headers.

Each header field consists of two parts, the field name and the field data. Header field names always appear at the beginning of a new line and they are separated from the field data by a colon. Most email applications only display a few select fields with the message body. The fields that are generally displayed by default are Date, Subject, To, From, and CC. The rest of fields are hidden from the user. However, most email client applications may display the full message headers when necessary.

Displaying message headers

Below are the instructions for displaying a full header listing with popular email applications:

Eudora

  1. Display the message in a separate window by double-clicking on it in the message index window.
  2. Once message is displayed in a separate window, click on the button that says "Blah Blah Blah" on it.

Thunderbird

  1. From the menu, select View, Headers, All. Or alternately, select "View Message Source"

Mac OS X Mail

  1. Display a message.
  2. Select from menu: View, Message, Long Headers.

Outlook Express

  1. Right click on the message and select Properties.
  2. Choose the Details tab and select the Message Source Button.
  3. If you want to forward the message with full headers, Select All (CTRL + A) and Copy (CTRL + C).
  4. Close the Message Source window and the Properties window.
  5. Select New Mail and position your cursor in the body of the email.
  6. Paste (CTRL + V) the copied information.
  7. Send the email.

Mutt and Pine

  1. Open the message.
  2. Press the h key.
  3. You can now forward this message normally, if necessary.

Mozilla 1.x

  1. Display the message.
  2. Select from Menu: View > Headers > All.
Updater: Mikael Hansen. Last reviewed: July 01, 2009