Eudora Pro
Double-click on the message to open it in a separate window.
Click on the button labeled "BLAH BLAH BLAH" at the top of the window. This will show the message headers.
You can then highlight and copy the headers into a new message.
Gmail
While viewing a message, click on "More Options".
Click on "Show Original".
This will display the headers for that message in a new window.
You can then highlight and copy the headers into a new message.
GoDaddy Webmail
Click on the message in your Inbox to open it
From the "Apply this Action" drop-down, select "View Full Header"
Click "Apply"
You can then highlight and copy the headers into a new message.
Hotmail
Once logged into hotmail, click on "Options"
Click "Mail".
Click on "Mail Display Settings".
Change the "Message Headers" section to "Advanced".
Click "OK".
Now when you read an e-mail, it should show you the full message headers.
Lotus Notes
Lotus Notes 4.6
Open the properties box on the message (in the default installation of the Notes Client, it will be the first smart icon on the left, but you can also right-click on the document and choose properties from that menu).
Choose the second tab on the properties box, which is a list of fields and their contents.
Scroll down to the field "Additional Headers".
You should then be able to copy/paste the headers into a new message.
If Notes will not permit you to select the contents of the field, you'll have to manually copy them to a new message - please be very careful in doing so.
Lotus Notes 5.x
Single click on the subject line without opening the document to full screen.
Select "File" (upper left) then select "Export"
Name the file
Select "Export"
Click on "Selected Documents"
Select "OK"
You can then attache the file to a new message.
OS X
After opening the "Mail" app, click the on the "Mail" drop-down menu and select "Preferences".
Click on the "Viewing" icon.
Click on the arrow on the Show header detail and select All.
You will now see the full headers of each message you view.
Thunderbird
Double-click the e-mail you want to view the headers for.
Click on the "View" drop-down menu and select "Headers" and then select "All".
This will show the headers for any message you view.
Microsoft Outlook
Microsoft Outlook 98, 2000, 2002, 2003
Double-click on the message to open it in a separate window.
Click on "View" and then "Options" on the drop-down menu at the top of the window.
Look for the section titled "Internet Headers" near the bottom of the Options window.
You can now copy/paste content from that section into a new message.
Microsoft Outlook Express 5 & 6
Right-click on the message and select Properties.
Select the Details tab.
You should see a section titled "Internet Headers" for this message.
You can now copy/paste content from that section into a new message.
Yahoo
Once you are logged in, click on "Mail Options".
Click on "General Preferences".
Under the "Messages" section, select "Show all headers" on incoming messages for the Headers option.
Click Save.
You should now see the full headers of every message you view.