Please obtain the full headers of the affected message, steps as follow


      Gmail

  1. Log in to Gmail
  2. Open the message you'd like to view headers for.
  3. Click the down arrow next to Reply, at the top of the message pane.
  4. Select Show Original.

The full headers will appear in a new window and click "Download Original" and return the file.

Outlook

  1. Open Outlook.
  2. Open the message by double-clicking on it.
  3. Click on the File tab.
  4. Click on Properties.
  5. In the Properties dialog box, the headers appear in the Internet headers box.

For older versions of Outlook:

  1. Open Outlook.
  2. Open the message you'd like to view headers for.
  3. Click the View menu, and select Options....

The full headers will appear in a new window.

Apple Mail

1. Open Apple Mail.

2. Click on the message you'd like to view headers for.

3. Go to the View menu.

4. Select Message, then Long Headers.

The full headers will appear in the window below your inbox.