Email to friend
* Your name:
* Your email:
* Friend's email:

E-mail headers, how to turn them on, why they are useful, and how they can help you reduce SPAM

The header of an e-mail is the part of an e-mail message that contains the “who, what, where” information. The most common headers are the “To:”, “From:” and “Subject” lines. Carbon Copy, “CC:” is another one you might see often. There are many other headers you could see in a message but you may not have access to edit them.

These headers contain information about the mail program used to create the message, what mail server sent the message, what mail server received the message, a message id that is used by the sending server, etc.

By default, most e-mail programs only display a few headers, “To:”, “From:”, “Subject:”, maybe “CC:”, and maybe “BCC:”. With the volume of SPAM mail, unsolicited e-mail, the additional headers can be used to determine where the SPAM came from, since most of the time the “From:” field contains a fake address.

Headers in Thunderbird

To view mail headers in Thunderbird, select View from the menu bar, Headers..., All

Headers in Webmail

If you use Webmail, mail headers are viewed by selecting the Message Source menu when viewing a single message. After doing so, a new window pops open with all the message headers, and the entire message content, visible. You can select the contents of this window, copy it to the clipboard, (Control-C on Windows, Command-C on a Mac) and paste it into a new message if you intend to forward the headers to someone.

Headers in Outlook

If you use Outlook Express, mail headers are turned on/off in the View menu. Pull down to All Headers.

Comparison of header information in two different header views

Here’s an example showing the difference in headers between having a default listing visible and having all the headers visible. First, “normal” mail headers:

Date: Wed Jan 23, 2002 08:13:41 AM US/Central
Subject: KVUE Email Forecast

Here’s the same example with all the headers visible:

Date: Wed Jan 23, 2002 08:13:41 AM US/Central
Subject: KVUE Email Forecast
Return-Path: <>
Received: from ( []) by (8.11.6/8.11.6) with ESMTP id g0NEMT904479; Wed, 23 Jan 2002 08:22:30 -0600
Message-Id: <>
Mime-Version: 1.0
Content-Type: text/html; charset=iso-8859-1
Content-Transfer-Encoding: quoted-printable
X-Ecs-Mailscanner: Found to be clean

Having all headers visible is important if you want to try and reduce the amount of SPAM mail. Here at SU, you can forward the offending e-mail to with ALL HEADERS turned on. It is very important to have the headers turned on. Without all headers visible, there is insufficient information for the mail adminstrators to block any further mail from that address.