In Mail, you could take a look at the source code data for any email quickly.

Here’s how to see it.

Open an email in theMailapp on your Mac.

The Raw Source command

SelectView>Message>Raw Sourcefrom the menu to kick off the source code in a separate window.

Alternatively, use the keyboard shortcutOption+Command+U.

The source code will open in a new window.

Source code for a message in Apple Mail

To save the source code to your desktop or print it out for further study, useSave asorPrintin theFilemenu.

The Save As and Print commands