All the messages sent to this specific email will be recorded as feedback to the Product with this ID.
The only requirement for the forwarded message is: it must contain a combination of words "forwarded" followed by an email address that it was initially sent from, f.e. "forwarded from [email protected]" or the following block:
Such a block is created automatically when you forward a message from the Gmail interface, so you don't have to worry about it when forwarding messages from inside Gmail. Otherwise, you have to add such a combination manually.