Prima facie this is impossible but perhaps someone has some kind of hack to do it. This is one of the last things holding me back from switching to Gmail from Pine.
To be clear, bouncing a message is like forwarding but leaving all the headers intact. It sort of amounts to spoofing the email, which perhaps is why Gmail doesn't support it. To the recipient of a bounced email, it seems as if they were just BCC'd.
Best Answer
Sam Ruby posted a workaround:
X-From_:. Copy this line to the top of the file, then modify that first line by removing theX-and_:characters. Save the file.mutt -f mail.google.com) and use thebcommand to bounce the message. Enter the name of the mailing list (example:public-html@w3.org), press enter and thenyto confirm.