Let's keep two things distinct: showing headers and forwarding headers.

You control which headers you see on your computer: View (menu) > Headers

E-mail service providers want to see headers. They sometimes ask for messages to be forwarded to them as attachments. That method preserves the original headers. Message (menu) > Forward as > Attachment.

You can forward messages that way without ever having to see all headers yourself. You do not need to show and then hide headers on your computer.

Thank you. Right now, when I forward any email, it forwards the entire header, exposed. I wish to contine to forward with an in-line reply, but I do not wish to display the full header

Oh, I understand better what you want and why you want it. I also understand better what Thunderbird does. Apparently, if View - Headers is set to "All", Thunderbird includes all the headers in the body of a forwarded message. If View - Headers is set to "Normal", Thunderbird does not include all the headers in the body of a forwarded message.

Does that setting do what you need?

And the only way that I know to include headers with a forwarded message without showing the headers is to forward the message as an attachment.

Rick,

Exactlly! "if View - Headers is set to "All", Thunderbird includes all the headers in the body of a forwarded message. If View - Headers is set to "Normal", Thunderbird does not include all the headers in the body of a forwarded message."

How do I change View Headers?

Thank you. I found the setting and fixed it.

It is in the home screen on the Tool Bar. View

--- Headers
---- Normal

Thanks for getting me in the right direction!

Or press <alt> to see the application menu, which, in my opinion, should not have been hidden by the developers.