I also do similar with our snailmail now.
Why should I accept snailmail spam when I don't accept email spam?
Anything that shows up in my mailbox out front who I don't know who its from or its obvious junk, I use a black marker to scribble out any bar codes on it, then glue a return to sender label over my address.
[bar code is read by computer, has to be blacked out so they have to open the mail to see who sent it back.]
I just print a bunch of these out on crap paper then wood glue them on the mail, so it can't be removed, so they have to open the junk mail.
And the post office makes money on the return shipping charges.
Help with them budget short falls
