You can compose a message and then drag-and-drop a received message into the composition window: aim for the attachment area to the right of the address fields and the attachment window will open. I don't know if that will include any files that were originally attached to the message you drag-and-drop but you could experiment. There was an add-on ('withAttach') to provide the function you request but development seems to have been abandoned, maybe because of this drag-and-drop feature?

I was hoping for a way that the function could be executed with just one click rather than a bunch of hand operations After thinking about it a FORWARD as ATTACHMENT with ORIGINAL SENDER function would work. I am looking at using this to report SPAM emails to our provider and spa,@uce.gov. So being able to also automatically add in additional email address(es) would make it real easy. I assume it is possible that the REPLY address is a spoofed address and this whole idea may not be worthy. I am assuming by including the spam email as an attachment the routing information is in the header section which can possibly be traced.

Thanks, I understand what you are trying to do. Have you looked at the 'forward' add-on? The description isn't very clear to me, but it says that it adds the functionality to the 'message context menu' so it might be what you want. Perhaps try it out?