SPAM perps often argue that they have a "right" to send email. Baloney! Don't SPAM perps have a right to free speech? Of course they do. So do you, and so do I (unless you live in a dictatorship). But as somebody more clever than I once said, "Your right to free speech ends at my front gate". While you have a right to talk to yourself on my street, you do NOT have a right to come into my home uninvited and start expounding your ideas or selling your wares, unless I explicitly say words like "come on in". The mere act of having a sign with my street number, or even opening my door to see who is knocking does not give you permission to barge in. Similarly, listing my email address does not give anybody permission to barge into my mailbox and start spewing trash.
Folks it really is that simple. Forget the legal mumbo-jumbo that US Congress and some perps rely on. Perps' right to free speech ends before they get into my mailbox. Period.