Uh oh!....a dirty trick.......
Maybe I shouldn't be too proud of this scheme to give a meaningful reply to irritating solicitations, but heck! It's too much fun!
I often receive solicitations for "prepaid legal services", various religious entities which in fact, are actually businesses, scam credit card applications, etc. You get the message, they all want money.
Very often these solicitations come with a "Business Reply Mail" envelope"; "postage will be paid by addressee". I take great pleasure when I find one that's particularly irritating and taping the envelope securely to a brick, or box of something heavy (brake rotor, exhaust manifold or other trash) and depositing it in the corner mailbox. (No return address, of course) These are handled first class only and even carry a surcharge for the return function. The USPS will deliver them, and make money doing so. This is a good way for the New York law firm (or whoever) to pay $12. or $14. or more for the return mail.