There are many situations when a system administrator needs to see the full headers of an email message, e.g. for checking compromised accounts or message flow through the various servers. When you “forward” a message your email program creates a new message and includes the email body as the forwarded portion. All of the technical information in the original emails header is no longer available and makes diagnosis very difficult. For this reason system administrator will ask to see the full headers or forward as an attachment.

If you email program is Outlook (windows)

1. Create a new message
2. Select Attach Item from the toolbar
3. Select Outlook Item
4. Browse to the message you are forwarding and select to attach it

or

1. Create a new message
2. Move and resize the window so that you can see your messages list
3. Select the email that you want to forward
4. Drag and drop it in to the body of your new message

To view the full headers of the message

1. Open the message
2. Select File | Info | Properties
3. The headers are in the section marked internet headers
4. Click in the Internet Headers section then press Ctr + A to select all
5. Copy this with Ctrl + C and then paste into a forwarded copy of the message with Ctrl + V

If you email program is Outlook 2011 or 2016 (Mac)?

Sometimes to troubleshoot a problem you are having ITS needs to see the complete message that you received including the header information. We usually prefer this to be sent as an attached item where possible.

1. Start a new message.
2. Move and resize the window so you can see your messages list.
3. Select the email that you want to forward.
4. Drag it and drop it into the body of your new message.

If your email program is OWA

1. Create a new message
2. Move and resize the wondow so you can see your messages list
3. Select the email that you want to forward
4. Drag it and drop it in to the body of your newly created message

or

1. Open the message (usually by double clicking on it)
2. click on the ellipsis (the 3 dots) to the right of “Forward” to open a drop down menu
3. Click view message details
4. Select all the text and copy it
5. Close the header information window
6. Click on the forward icon of your message
7. Paste the copied text at the beginning of the message
8. send the message

If you email program is not listed above

check this link to Google article