Follow these instructions to forward full headers in Apple Mail.

  1. Launch Apple Mail application.
    • Apple Mail.png
  2. Open the email in question, so we may get to the message's headers.
  3. Go to the "View" menu, select the "Message" sub-menu, and select the "Raw Source" option.
    • Apple Mail - Full Header - 1.png
  4. A new window will appear with all the Raw Email Source information, from here press the Select All keyboard combination, to select all of the Raw Source information: Command (⌘)-A
    • Apple Mail - Full Header - 2.png
  5. Now press the Copy keyboard combination, to copy the selected Raw Source: Command (⌘)-C
  6. Going back to the email message, click the Forward button:
    • Apple Mail - Full Header - 3.png
  7. Now, within the Forward message editor, press the Paste keyboard combination, to paste the copied Raw Source: Command (⌘)-V
    • Apple Mail - Full Header - 4.png
  8. Now enter the recipient's (To) address and Send the email message.

For more information on Apple Keyboard Combinations, check out Apple's Support Page: