A bounce message can be very small, specifying only three fields: To, From, Date to identify the rejected message. Compared to this spam messages would be much

A bounce message can be very small, specifying only three fields: To, From, Date to identify the rejected message. Compared to this spam messages would be much bigger, consisting of html, css, javascript, pdf attachmens, zipped executables etc. The message could be sent to a fixed address, like abuse@same.server; how to check messages on that address is a different story as it's not user messages, but technical messages.