As a matter of course, emails contain much essential information in their header area: the sender, recipients, subject and much tracking information. The latter can be used to troubleshoot email problems, for instance, or to trace the odd unwelcome message back to its likely origin.
In Gmail, getting to all these heady and potent bits, is easy.
See Full Email Headers in Gmail
To get a message's full email headers displayed in Gmail:
- Open the email message in Gmail.
- Click the down arrow (More) next to the Reply button in the top right corner for the email whose headers you want to see.
- Select Show original from the menu that comes up.
The full message source will open in a new browser window or tab with the header lines on top; everything before the first empty line from the top is part of the message header.
(Updated February 2012)