Gmail

1. Log in to Gmail

2. Open the message you'd like to view headers for

3. Click the down arrow next to Reply, at the top of the message pane

4. Select Show Original

Microsoft Outlook

1. Open a message

2. On the Message tab, in the Options group, click the Dialog Box Laucher Icon image

In the Message Options dialog box, the headers appear in the Internet headers box.

Microsoft Outlook 2010

1. In an open message, click the File tab

2. Click Properties

Header information appears in the Internet headers box.

Microsoft Outlook 2007

1. Open the email in a new window by double-clicking it

2. Click the expansion button in the lower right corner of the Tags toolbar box

3. The box, by default, holds the Follow Up and Mark as Unread buttons

4. In Outlook 2007, the box is labeled Options

5. Find the headers under Internet headers

Mozilla Thunderbird

1. Open the message in the reading pane, in a new tab or in a new window.

2. Select View | Headers | All from the menu.

Click the menu button first if you see no menu bar.

If your e-mail client is not listed on this page, please see this article.