How to Obtain Headers from Email

Below are step-by-step instructions for displaying email header information within several email apps.
Gmail
In Gmail, click on the email you would like to view headers for.
Click the three-dot 
three-dot icon icon  next to the Reply button.
Select Show Original.
Show Original
Mac Mail
Open the email.
Click on the View menu on the Menu Bar.
Select Message, then Long Headers.
Selecting Long Heading from the Message drop-down in the View menu.
Outlook 2011
Right-click on the email that you would like to view the headers for (or use Shift +Click)
Click View Source.
This will open a text file with the Header Information outlook source code.
Outlook 2010
Open the email.
Click the File Tab.
Select Properties.
The information will be listed under the Internet Headers section out look properties.
Outlook 2007
Right-click the email (or use Shift + Click).
Choose Message from the menu.
The information will be listed under the Internet Headers Section outlook message options.
Thunderbird
Select the email.
Click on View.
Click on Headers.
Click on All.
Click the “Forward” button and all header information will appear at the top of the email.