I have a chain letter I composed that I have been sharing for about 20 years. Please note: IT DOES NOT IN ANY WAY INVOLVE MONEY! (Chain letters are legal if they don't involve cash.) AND IT DOES NOT INCLUDE A THREAT/CURSE. (This would actually be legal [i.e., a threat/'curse']. But I just don't think that would be very nice.) The only problem is finding addresses. FWIW I tried sending it via Hotmail about 20 years ago. But I found out the hard way Hotmail doesn't permit chain letters, even if they are legal and cutesy. So how do I find random addresses? No need to lecture me on how silly and pointless it is to send chain letters. But if you must... Again, my chain letters never involved money, and never will.
I bet you could find a bunch of random addresses using google maps... maybe. But who gets mail anymore?