My way of handling this is to have multiple email accounts. One is my "junk mail" account. This one is given out freely to just about anyone. Supposedly it was closed about 10 years ago when we moved. Somehow the "disconnect order" got misplaced.
One of my accounts is a private account only a few of my friends know and use. Others are for various needs for businesses with legitimate reasons to contact me.
It keeps most of the junk in one place and easier with which to deal. It is amazing how when one site gets your eddress it is often shared with a dozen others.
Most people who have been given my eddress also know it is not viewed by me kindly if they share my information.
The MacOS mail reader used to have a "bounce" option for unwanted email. It would send it back looking like it was rejected as a bad eddress. This did help with some automatic spam generators.
It isn't hard to generate a message to get bounced and then with a little editing make it look like it isn't a forwarded message to fool an auto-mailer.
jtk
"A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
- Sir Winston Churchill (1874-1965)